A picture coding apparatus includes a picture feature amount extracting unit which extracts respective feature amounts of the current picture and a picture having a specific relationship with the current picture; a correlation degree calculating unit which calculates, based on the feature amount extracted by the feature amount extracting unit, a correlation degree indicating a degree of image similarity between the current picture and the picture having a specific relationship with the current picture; a picture type determining unit which determines, depending on the calculated correlation degree, a picture type for the current picture, from two picture types on which different inter-picture prediction is performed; and a coding unit which codes the current picture according to the determined picture type.