To reduce the computational complexity of the emerging High Efficiency Video Coding(HEVC),a novel fast coding algorithm based on quad-tree type analysis and Coding Unit(CU)pruning was proposed.First,the CU Depth Range(DR)of an encoded Largest CU(LCU)was determined by analyzing its quad-tree type.Then,the DR of the current LCU was predicted based on those of neighboring LCUs and the co-located LCUs in the previously coded reference frame which was before or after current frame.The CU depth range of the current LCU could be determined based on the predicted DR.The proposed method also took advantage of Bayesian decision to obtain thresholds,bywhich early CU pruning could be determined.Experimental results show that the proposed method reduces encoding time by 41.55%on average in a random access case.Compared with the original HEVC encoding scheme,Bjontegaard delta bitrate(BDBR)increment is 1.94% and BD-PSNR loss is 0.06 dB.Compared with Shen's algorithm,it saves 12% encoding time with a BDBR increment of 1.09% and a BD-PSNR lossof 0.03dB.