diff --git a/_locales/ja/Grove-strings.json b/_locales/ja/Grove-strings.json
index e259c7a..8b42b5d 100644
--- a/_locales/ja/Grove-strings.json
+++ b/_locales/ja/Grove-strings.json
@@ -20,5 +20,8 @@
   "grove.TM1637.set|block": "%strip|[Grove - 4桁ディスプレイ]|明るさを|%level|に変更する",
   "grove.TM1637.bit|block": "%strip|[Grove - 4桁ディスプレイ]|%dispData|を|%bitAddr|桁目に表示する",
   "grove.TM1637.point|block": "%strip|[Grove - 4桁ディスプレイ]|コロンの表示を|%point|に変更する",
-  "grove.TM1637.clear|block": "%strip|[Grove - 4桁ディスプレイ]|表示を消す"
-}
\ No newline at end of file
+  "grove.TM1637.clear|block": "%strip|[Grove - 4桁ディスプレイ]|表示を消す",
+  "grove.aht20ReadTemperatureC|block": "[Grove - 温湿度センサー]|温度（℃）を読み取る",
+  "grove.aht20ReadTemperatureF|block": "[Grove - 温湿度センサー]|温度（℉）を読み取る",
+  "grove.aht20ReadHumidity|block": "[Grove - 温湿度センサー]|湿度を読み取る"
+}
diff --git a/blocks/GroveAHT20.ts b/blocks/GroveAHT20.ts
new file mode 100644
index 0000000..a4ad5eb
--- /dev/null
+++ b/blocks/GroveAHT20.ts
@@ -0,0 +1,71 @@
+/**
+ * Grove - AHT20 Custom Block
+ */
+//% groups=['AHT20']
+namespace grove
+{
+    function Read(aht20: grove.sensors.AHT20): { Humidity: number, Temperature: number }
+    {
+        if (!aht20.GetState().Calibrated)
+        {
+            aht20.Initialization();
+            if (!aht20.GetState().Calibrated) return null;
+        }
+
+        aht20.TriggerMeasurement();
+        for (let i = 0; ; ++i)
+        {
+            if (!aht20.GetState().Busy) break;
+            if (i >= 500) return null;
+            basic.pause(10);
+        }
+
+        return aht20.Read();
+    }
+
+    /**
+     * Read the temperature(°C) from Grove-AHT20(SKU#101990644)
+     */
+    //% group="AHT20"
+    //% block="[Grove - Temp&Humi Sensor]|Read the temperature(°C))"
+    //% weight=3
+    export function aht20ReadTemperatureC(): number
+    {
+        const aht20 = new grove.sensors.AHT20();
+        const val = Read(aht20);
+        if (val == null) return null;
+
+        return val.Temperature;
+    }
+
+    /**
+     * Read the temperature(°F) from Grove-AHT20(SKU#101990644)
+     */
+    //% group="AHT20"
+    //% block="[Grove - Temp&Humi Sensor]|Read the temperature(°F))"
+    //% weight=2
+    export function aht20ReadTemperatureF(): number
+    {
+        const aht20 = new grove.sensors.AHT20();
+        const val = Read(aht20);
+        if (val == null) return null;
+
+        return val.Temperature * 9 / 5 + 32;
+    }
+
+    /**
+     * Read the humidity from Grove-AHT20(SKU#101990644)
+     */
+    //% group="AHT20"
+    //% block="[Grove - Temp&Humi Sensor]|Read the humidity"
+    //% weight=1
+    export function aht20ReadHumidity(): number
+    {
+        const aht20 = new grove.sensors.AHT20();
+        const val = Read(aht20);
+        if (val == null) return null;
+
+        return val.Humidity;
+    }
+
+}
diff --git a/pxt.json b/pxt.json
index 51bb30d..102c4ef 100644
--- a/pxt.json
+++ b/pxt.json
@@ -9,8 +9,10 @@
     "files": [
         "README.md",
         "main.ts",
+        "blocks/GroveAHT20.ts",
         "_locales/ja/Grove-strings.json",
-        "_locales/de/Grove-strings.json"
+        "_locales/de/Grove-strings.json",
+        "sensors/AHT20.ts"
     ],
     "testFiles": [
         "test.ts"
diff --git a/sensors/AHT20.ts b/sensors/AHT20.ts
new file mode 100644
index 0000000..bcd311e
--- /dev/null
+++ b/sensors/AHT20.ts
@@ -0,0 +1,87 @@
+namespace grove
+{
+    export namespace sensors
+    {
+
+        export class AHT20
+        {
+            public constructor(address: number = 0x38)
+            {
+                this._Address = address;
+            }
+
+            public Initialization(): AHT20
+            {
+                const buf = pins.createBuffer(3);
+                buf[0] = 0xbe;
+                buf[1] = 0x08;
+                buf[2] = 0x00;
+                pins.i2cWriteBuffer(this._Address, buf, false);
+                basic.pause(10);
+
+                return this;
+            }
+
+            public TriggerMeasurement(): AHT20
+            {
+                const buf = pins.createBuffer(3);
+                buf[0] = 0xac;
+                buf[1] = 0x33;
+                buf[2] = 0x00;
+                pins.i2cWriteBuffer(this._Address, buf, false);
+                basic.pause(80);
+
+                return this;
+            }
+
+            public GetState(): { Busy: boolean, Calibrated: boolean }
+            {
+                const buf = pins.i2cReadBuffer(this._Address, 1, false);
+                const busy = buf[0] & 0x80 ? true : false;
+                const calibrated = buf[0] & 0x08 ? true : false;
+
+                return { Busy: busy, Calibrated: calibrated };
+            }
+
+            public Read(): { Humidity: number, Temperature: number }
+            {
+                const buf = pins.i2cReadBuffer(this._Address, 7, false);
+
+                const crc8 = AHT20.CalcCRC8(buf, 0, 6);
+                if (buf[6] != crc8) return null;
+
+                const humidity = ((buf[1] << 12) + (buf[2] << 4) + (buf[3] >> 4)) * 100 / 1048576;
+                const temperature = (((buf[3] & 0x0f) << 16) + (buf[4] << 8) + buf[5]) * 200 / 1048576 - 50;
+
+                return { Humidity: humidity, Temperature: temperature };
+            }
+
+            private _Address: number;
+
+            private static CalcCRC8(buf: Buffer, offset: number, size: number): number
+            {
+                let crc8 = 0xff;
+                for (let i = 0; i < size; ++i)
+                {
+                    crc8 ^= buf[offset + i];
+                    for (let j = 0; j < 8; ++j)
+                    {
+                        if (crc8 & 0x80)
+                        {
+                            crc8 <<= 1;
+                            crc8 ^= 0x31;
+                        }
+                        else
+                        {
+                            crc8 <<= 1;
+                        }
+                        crc8 &= 0xff;
+                    }
+                }
+
+                return crc8;
+            }
+
+        }
+    }
+}