Abstract: Research to the failure probability has been performed for a planed installation of parallel oil & gas pipelines in China. The statistics related to the failures of oil pipelines issued by a European company, CONCAWE and the data related to European natural gas pipelines accidents issued by EGIG have been used as the basic data for failure probability. Upon completion of correction and fine-tuning, corrected values for failure probability related to oil pipeline and natural gas pipeline installed in parallel way can be determined. In accordance with event tree and probability of oil pipelines induced by failure of natural gas pipeline, failure probability of parallel oil pipelines can be determined to be 6.66×10^－5 km/yr, which is no more than 0.9% higher than the failure probability of pipelines installed independently. In addition, additional risks related to parallel pipelines can be calculated with consideration to consequences of pipeline failures. Through comparison between calculated risks and acceptable risks, it can be determined that parallel installation of two pipelines is acceptable.