The grade evaluation of the welding filler material（hereinafter referred to as: welding material evaluation） is the grade-selecting process for the batches of welding materials used for civil nuclear power installation; it provides the basis for the utilization of the specific grade of welding material on construction site. The practice of evaluating the welding material grade used for M310 PWR nuclear power installation engineering is analyzed and the issues that are prone to emerge during the process is discussed, which provides referable information for the grade evaluation of the welding materials used for M310 PWR nuclear power installation engineering.