A picture prediction encoding device includes: a region division unit for dividing an input picture into a plurality of blocks; a prediction signal generation unit for generating a prediction signal with respect to a pixel signal that is included in a subject block to be processed among the blocks; a residual signal generation unit for generating a residual signal between the pixel signal of the subject block and the generated prediction signal; a signal encoding unit for generating a compressed signal by encoding the residual signal; and a storage unit for decompressing the compressed signal and storing the decompressed signal as a reproduced pixel signal. The prediction signal generation unit is configured to sub-divide the subject block into a plurality of small regions, at least one of the small regions is non-square, and a length of a first side of the non-square small region is longer than a length of a second side that is different from the first side.