This study develops a portable ECG signal measurement and monitoring system for application in telecare. To overcome the shortcoming of traditional measurement systems that lack of mobility, an Android-based portable device is employed to deal with the electrocardiogram (ECG) signal. The processed ECG signal can then be transmitted to remote healthcare server via mobile communications or WiFi networks for healthcare purpose. Firstly, a circuit connected to Android-based portable device is implemented to extract analog ECG signal. The portable device then digitizes the analog ECG signal and displays the ECG waveform and heart rate on the screen, and finally transmits the results to remote healthcare center for health monitoring and diagnosis. Experimental result indicates that the developed system is able to transmit the ECG signal in a real-time manner for aiding telemedicine, therefore has the potential in enhancing quality of emergency medical service.