Abstract: Gas pipelines in China have gradually entered the stage of frequent accidents, and gas leakage will increase the safety risk of pipeline operation, even resulting in personnel casualties. By investigating and survey, the progress of researches on the leakage and diffusion of gas pipeline was demonstrated in terms of leakage and diffusion model, numerical simulation, experimental research and soil-atmosphere coupling. Additionally, the current problems of research on leakage and diffusion of gas pipelines were discussed and pointed out. Definitely, most of the present researches focus on the gas leakage of the simple pipe galleries and the overhead pipelines, but little research is on the leakage of buried pipelines. The factors affecting the leakage are not fully considered, with few results on high-pressure pipeline leakage, multi-point leakage superposition influence and leakage sourcing obtained. Most of the soil properties are treated simply in the study of the leakage law of buried pipelines. Moreover, there are few studies on the comparison between numerical simulation and experiment, and the accuracy of simulation results remains to be verified. Conclusively, the research results could make a good preparation for the coming high incidence period of gas pipeline leakage in China in theory and practice.