Abstract: Aim Describes a method for the determination of warhead storage period va- lidity based on finite test data of property variations of ammunition kept in stock. Methods Some warheads gone through different stock time were randomly sampled. Features of their loss of efficacy, storage safety and reliability were obtained by test analysis of the explosive in warhead, and relevant function models were established ap- plying grey system theory. The storage period of validity of warhead is obtained ac- cording to stipulations in ammunition storage and management. Results The predicted value for a certain warhead is in good accord with the test results.Conclusion The described method can be used in calculating the storage period of validity of existing. ammunitions kept in stock.