Abstract: Briefed in the essay is the perforating operation in oil & gas well completion.Summerized is the influence of perforation parameters on well productivity.Also analyzed are the difference between domestic and oversea perforating guns as well as the difference between their technological levels.Learning from the research of the technology in ordnance industry and the mechanics of explosion，the effect of material properties of perforating gun on perforating performance is elaborated.The main cause of brittleness at the crack is found by studying the morphology of the crack arrest section at the big crack on the perforating gun body after firing live charges.The difference between domestic and oversea developments on materials for gun body with blind holes is compared and analyzed.The latest perforating technologies and products from different companies are introduced.Furthermore，the properties of a newly-developed type of high strength and toughness seamless steel tube for perforating gun are introduced.