The image predictive encoding device 10 comprises an intra frame predictive signal generation method determination section 15 which determines, for adjacent areas comprising regenerated pixel signals and adjacent to the target area, a predictive method which is derived on the basis of data corresponding to the adjacent areas as an R mode predictive method or an L mode predictive method, an intra frame predictive signal generation section 16 which generates an intra frame predictive signal on the basis of the R mode predictive method thus determined, and a subtractor 18, a transform section 19, a quantization section 20, and an entropy encoding section 25 which encode a residual signal of a pixel signal of the target area on the basis of the generated intra frame predictive signal.