A new high capacity reversible watermarking algorithm based on image interpolati on is proposed.Firstly,the input image is down-sampling processed and an new cover image is generated by using interpolation method on down-sampling image is generated.Secondly,the cover image is divided into blocks,and the maximum and minimum of four reference pixe ls of each block are obtained,and then the differences of three non-reference pixel of each block are calculated.Depe nding on these differences,the number of bits which can be embedded in each non-reference pixel can be obtained.Finally,a bit str ing of each non-reference pixel is converted to corresponding decimal digit,and then the non-reference pixel is modified by this decimal digit to embed watermarking signal.A large number of experimental results show that the proposed algorithm does not appear pixel value overflow/underflow problem,and can achieve reversible data hiding.Compared with similar reversible watermarking algorithms,it has higher embedding capacity.Und er the same embedding rate (ER),it has also better performance.