In this paper we are interested in modeling, simulation, and measurement of laser spot position determination circuit (LSPDC) with a quadrant detector (QD). Photodiode is modeled using its differential equations then implemented using ORCAD –pspise. Starting with the output of the detector, the circuit modeling and simulation for the preamplifier, post amplifier, ADC and microcontroller card were performed. PCB card implementation was performed and integrated with the QD and the necessary optical system components. The implementation of the full LSPDC with the detector is performed. General system for testing the spot LSPDC was performed with a laser source simulating the incident radiation and a mechanical system to enable adjusting different angles. Good agreement was achieved between the measured data and the adjusted angles with a small error attributed to the error in the adjusted mechanical system and the stability of the used laser source.