The present technique relates to an information processing apparatus, an information processing method, a program, and an information processing system capable of efficiently and temporarily storing contents in a case where the contents are played back using a play list. A calculation unit calculates, on the basis of a play list indicating contents adopted as a playback target chosen from among a plurality of contents, a priority level about a cash temporarily storing the contents, for each of the contents. For example, the present technique can be applied to an information processing system and the like performing streaming playback of contents based on MPEG (Moving Picture Experts Group phase)-DASH standard.