Abstract: According to the defects of CORDIC algorithm, a modified CORDIC algorithm is proposed in rotation mode.It needn't look-up table and scale factor correction and can realize the calculation of many transcendental functions only by simple shift and addition-subtraction operation, which can reduce the cost of hardware and improve operational performance.The proposed algorithm is suitable for all the rotation angles by repeated iteration and domain transformation.The error analysis shows that the error of the proposed algorithm is very small.