A subject information processing apparatus comprising: signal processing means configured to: receive electrical signals output from a probe detecting acoustic waves propagated from a subject in response to an irradiation of light onto the subject, the electrical signals being acquired for N positions of the probe that are different relative positions to the subject and at different timings, where N is 3 or a larger integer, a position of the probe defining a position of highest receiving sensitivity of the propagated acoustic waves, and a high resolution region being defined by the position of highest receiving sensitivity; and generate N pieces of image data of the subject based on the received electrical signals; and display control means configured to control display means to display an image based on the generated N pieces of image data, wherein the signal processing means is configured to combine a series of at least two of temporally consecutively obtained i-th image data to (i + m)-th image data, where i + m < N, and i and m are natural numbers, out of the N pieces of generated image data to generate first combined image data, the i-th image data to the (i + m)-th image data being generated from the electrical signals received for positions of the probe having overlapping high resolution regions, wherein the signal processing means is configured to combine a series of at least two of temporally consecutively obtained (i + n)-th image data to (i + n + m)-th image data, where n is a natural number, out of the N pieces of generated image data to generate second combined image data, the (i + n)-th image data to the (i + n + m)-th image data being generated from the electrical signals received for positions of the probe having overlapping high resolution regions, and wherein the display control means is configured to control the display means to display an image based on the first combined image data, and to further update the image displayed on the display means to an image based on the second combined image data so that the image based on the first combined image data and the image based on the second combined image data are displayed sequentially. signal processing means configured to: receive electrical signals output from a probe detecting acoustic waves propagated from a subject in response to an irradiation of light onto the subject, the electrical signals being acquired for N positions of the probe that are different relative positions to the subject and at different timings, where N is 3 or a larger integer, a position of the probe defining a position of highest receiving sensitivity of the propagated acoustic waves, and a high resolution region being defined by the position of highest receiving sensitivity; and generate N pieces of image data of the subject based on the received electrical signals; and receive electrical signals output from a probe detecting acoustic waves propagated from a subject in response to an irradiation of light onto the subject, the electrical signals being acquired for N positions of the probe that are different relative positions to the subject and at different timings, where N is 3 or a larger integer, a position of the probe defining a position of highest receiving sensitivity of the propagated acoustic waves, and a high resolution region being defined by the position of highest receiving sensitivity; and generate N pieces of image data of the subject based on the received electrical signals; and display control means configured to control display means to display an image based on the generated N pieces of image data, wherein the signal processing means is configured to combine a series of at least two of temporally consecutively obtained i-th image data to (i + m)-th image data, where i + m < N, and i and m are natural numbers, out of the N pieces of generated image data to generate first combined image data, the i-th image data to the (i + m)-th image data being generated from the electrical signals received for positions of the probe having overlapping high resolution regions, wherein the signal processing means is configured to combine a series of at least two of temporally consecutively obtained (i + n)-th image data to (i + n + m)-th image data, where n is a natural number, out of the N pieces of generated image data to generate second combined image data, the (i + n)-th image data to the (i + n + m)-th image data being generated from the electrical signals received for positions of the probe having overlapping high resolution regions, and wherein the display control means is configured to control the display means to display an image based on the first combined image data, and to further update the image displayed on the display means to an image based on the second combined image data so that the image based on the first combined image data and the image based on the second combined image data are displayed sequentially.