Passive Intermodulation(PIM) is one of the key reliability problems of the microwave circuits. With the development of microwave system integration and miniaturization, the microstrip circuits are widely used in the industry and studied by the researchers. Therefore, it has great value to investigate the physical mechanisms, the evaluation methods, and the suppression technologies of the PIM interference in the microstrip circuits. The nonlinearities in the microstrip circuits are usually distributed, which are usually different from that of the cavity based microwave devices, and they are also associated with the substrate materials, the fabrication processes and the device structures. All these make it difficult to solve the PIM problems in the microstrip circuits. Though more and more PIM investigations for the mircostrip circuits have been reported in recent years, the practical high-quality circuit-design still faces challenge. In this paper, we review the recent developments about the PIM phenomenon in the microstrip circuits including the nonlinearity mechanisms, the modeling and simulation methods, and the measurement technologies, which could provide comprehensive guidance for the future study of the PIM problems in the microstrip circuits.