A sphygmomanometer includes a pressure measuring unit connected to an analog-to-digital conversion unit, and the analog-to-digital conversion unit is connected to a microprocessor, and the microprocessor is connected separately to a setup unit, display unit, data storage unit, reminding unit and a power supply unit. The analog-to-digital conversion unit converts a blood pressure measured by the pressure measuring unit into data. Meanwhile, the microprocessor retrieves and compares the standard value of blood pressure pre-stored in the data storage unit with the measured value and displays the result on the display unit and the reminding unit. Users can change the predetermined setup of standard blood pressure values through the setup unit and users can understand the meaning of the complicated measured data through different colors or sounds of the backlight module of the reminding unit without memorizing the values, and determine whether the measured value is normal or critical.