Abstract： Objective To design and organize the ability test project(No.NIFDC-PT-420)to determine the hydrolytic resistance of pharmaceutical glass grains and evaluate the participants'ability to determine hydrolytic resistance of glass packaging materials.Methods The samples were prepared according to the procedures specified in the China National Accreditation Service for Conformity Assessment.The uniformity was tested before the sample distribution.Different interference samples were randomly distributed to prevent data collusion and forgery.Robust statistical method and z scores were used to evaluate the reported results.z scores were calculated with the median of all participants'reported results as the specified value and the standardized quartile distance as the standard deviation in the ability evaluation.Results The uniformity of the samples met the requirements of the proficiency test.Among the 42 laboratories,34 laboratory results were satisfactory,4 were suspicious and 4 were not qualified.The satisfaction rate was 81.0％.Conclusion This proficiency test objectively and scientifically evaluates the testing ability of pharmaceutical packaging materials in some laboratories in China.The testing ability of some enterprise laboratories need to be improved and drug regulatory authorities should pay attention to the testing ability building in such laboratories.