Abstract: Gas pipeline network is the bond between resources and markets, and its safety and stability are always hotspots in the oil & gas transportation and storage sector. Currently, researches on reliability assessment for operation and gas supply of gas pipeline network are still in a primary stage, whereas traditional theories on reliability cannot be used directly for this purpose. This paper reviewed the applicability and limitation of traditional theories in the reliability assessment of the units, operation and gas supply of the gas pipeline network, and indicated key issues in researches thereof. In addition, this paper illustrated the progress and prospects of the researches on reliability assessment for gas pipeline network, and summarized the results as reference for similar fields. There are several major issues to be considered in such assessment, including the development of a comprehensive and multi-dimensional system of indices for reliability assessments, the development of reliability assessment methods for specific units and systems through combination of traditional reliability theories and methods with the engineering practices of gas pipeline network, and the development of optimization model based on reliability for the operation features and user demands of gas pipeline networks.