A method of compressing an electrocardiography (ECG) signal and an ECG signal sensing apparatus thereof are provided. The method of compressing the ECG signal includes the following steps. A current first characteristic wave is identified and captured from the ECG signal. A set of difference is obtained by subtracting a previous first characteristic wave from the current first characteristic wave. A first encoding process is executed on the set of difference, so as to obtain a first bit stream. A compressed ECG data is generated, wherein the compressed ECG data at least comprises the first bit stream.一種心電圖訊號的壓縮方法以及其心電感測裝置。心電圖訊號的壓縮方法包括下列步驟。由心電圖訊號辨識並擷取目前第一特徵波段。以目前第一特徵波段減去先前第一特徵波段而取得一組差值。對該組差值執行第一編碼程序以取得第一位元流。產生壓縮心電圖資料,其中壓縮心電圖資料至少包括前述第一位元流。S220、S240、S260、S280‧‧‧心電圖訊號的壓縮方法的步驟
