A wearable device and physiological information system and method are provided. The wearable device includes a device body, a measurement circuit, and a measurement trigger interface. The measurement circuit is configured to execute a physiological information measurement operation for measuring physiological signal, so as to generate physiological information. The measurement trigger interface generates a measurement trigger signal when being triggered, in which the measurement circuit executes the physiological information measurement operation in response to the measurement trigger signal.一種穿戴式裝置、生理資訊監控系統及生理資訊監控方法。所述穿戴式裝置包括裝置本體、量測電路以及量測觸發介面。量測電路設置於裝置本體上，用以執行生理資訊量測動作以量測生理訊號，並且據以產生生理資訊。量測觸發介面經觸發而產生量測觸發訊號，其中量測電路反應於量測觸發訊號執行生理資訊量測動作。
