Generally, measuring the location and optical properties of pathological lesions in biological tissue is pretty helpful for accurate diagnosis and effective treatment of diseases. In order to have a further diagnosis, it is necessary to implement a further study on the distribution of light energy inside the pathological lesions. In this paper, we focused on the localization of lesions and measurements of light energy distribution inside the lesions using photoacoustic (PA) imaging. Ink blocks were used to mimic the lesions in the sample. Some graphite rods were utilized as probes to help mapping the light distribution in lesions. As a result, our experiments are able to locate specific lesions in the sample. Furthermore, this method can be used to uncover the light energy distribution inside the lesions and to analyze qualitatively the influences of optical properties of the lesions and the ambient medium on the light energy distribution. It is promising for our method in diagnosing tumors in the early stage and identifying benign and malignant lesions in clinical applications.