In order to reduce the complexity of intra frame coding of x265and reduce the time required for coding,a fast algorithm for the intra frame coding unit (C U) division and prediction unit (PU) mode selection for the high efficiency vide o coding (HEVC) standard is proposed in this paper.The famous differen ce matrix is used to calculate the texture complexity,and the relationship among the texture similarity of its sub CU and total number of bits required for enc oding and quantization parameter is used as the decision condition for the early termi nation of CU division.The value of the sum of absolute transformed difference (SATD) is calculated to further reduce the appropriate number of PU candidate lists of RDO in order to reduce the computational cost of the rate distortion.Experimental resul ts show that the proposed algorithm can reduce the encoding time by 32.34% on average when the peak signal to noise ratio (PSNR) is only reduced by 0.028dB and the bitrate is in creased by 1.27%.