Abstract: This paper represents sensorless state space model of BLDC motor .The BLDC is modeled as sub-blocks and these blocks are either logical or S-function blocks. The BLDC main block is designed using state space model. The Zero cross detection control technique of back-emf is used for commutation of power switching device in 3 phase inverter. Modeling is done using MATLAB/SIMULINK and no built in Simpower system tool box is used. Motor’s speed is controlled with PID controller and for current control, hysteresis current controller is used. By reading instantaneous position of the rotor as a one of the output of the state space model, different variables of the motor can be controlled without any external sensors hence motor is operating as sensorless.