A motion estimation method and a motion estimation apparatus for calculating a motion vector to estimate a current picture partially forming a video sequence on the basis of first and second reference pictures partially forming the video sequence. In the method and apparatus, a reference block included in the first reference picture similar to a current block included in the current picture is specified and multiplied by a first coefficient. By performing a subtraction between the multiplied reference block and the current block, a template block indicative of a difference between the multiplied reference block and the current block is obtained. On the other hand, candidate blocks are calculated by multiplying, by a second coefficient, each reference blocks included in a search window partly forming the second reference picture. Based on the candidate blocks and template block are calculated distortion values each indicative of a difference between the following interpolated blocks and current block. Each of the interpolated blocks is indicative of a mean between the specified reference block of the first reference picture and each reference blocks of the search window.