Photoacoustic tomography (PAT) is a new modality with a high-resolution and a high contrast, the reconstruction process of which can result in improvements of the imaging quality. The aim of this study is to present an attempt to develop a novel reconstruction method with a time reversal algorithm (TR) for the PAT in an inhomogeneous media. By incorporating the finite difference time domain method (FDTD), the imaging reconstruction with the TR algorithm was formulated firstly. Then, two numerical simulations and an ex vivo experiment were both carried out to evaluate the capability of the proposed method in this work. The obtained results showed qualitatively the PAT images could be reconstructed well both in an inhomogeneous numerical model from different scanning ways and in a phantom model embedded with an ex vivo tumor of patients. Although the TR based algorithms may cost a bit more time than another in reconstruction process, it would be more practical approach for photoacoustic tomography with arbitrary scanning ways and better capability of imaging in inhomogeneous media, could also encourage us to further discuss its applicability of tumor detection in patients.