A subject information obtaining apparatus has: a light source a plurality of receiving elements which receive acoustic waves generated from a subject, and output signals a memory unit for storing, for each of a plurality of predetermined positions, information to represent signals which are output from the plurality of receiving elements when an acoustic wave source is assumed to exist in the position and an estimating unit for estimating a distribution of acoustic wave sources. The estimating unit assumes a distribution of acoustic wave sources, obtains signals corresponding to positions of respective acoustic wave sources in the assumed distribution from the stored information, and defines a distribution of acoustic wave sources, of which degree of coincidence between the obtained signals and signals obtained in an actual measurement is highest, as the distribution of acoustic wave sources.
