Organic compound samples are characterized by mixed phase and amplitude, such as most polymer combination materials and biological soft tissues made from low-atomic-number materials etc, which are very hard to obtain higher resolution of density by conventional absorption computerized tomography (CT) or phase retrival algorithm of pure-phase object. The X-ray in-line phase contrast CT technology based on the modified Bronnikov algorithm has been utilized for the experimental investigation of high polymer mixed materials and medical samples. The experimental results show that the proposed method can realize the non-destructive imaging and precise measurement of polymer combination samples by distinguishing those electronic densities of different parts clearly. In addition, the results demonstrate the feasibility of three-dimensional measurement of medical samples with porosity by supplying with a valid threshold. The method has good potential application in material science, especially in polymers and foam porous materials, and three-dimensional nondestructive imaging of biomedicine due to the advantage of low radiation dose.