Ultrasonic range finder system consists of an ultrasonic sensor which operates like SONAR technology. The system consists of an 8051 microcontroller, LCD Display and an ultrasonic sensor. The sensor works on 40KHz and when a trigger signal of 10us is given it transmits a 40KHz wave and waits for the echo. Then an output pulse proportional to the time taken to receive the echo is produced. The microcontroller receives the signal and measures the width of the signal and converts it to its proportional distance. The distance is then displayed on the LCD. If no echo is received the microcontroller displays out of range or maximum indication on the LCD display. The system operates in a 5V power supply and the sensor is also 5V compatible. The project can be used to find out distance from objects precisely.