This paper was performed research for the total filtration in the useful beam of 45 diagnostic x-ray equipments using in Korea. We obtained the following results: 1. A good ability of total filtration was showed in higher than lower maximum permissible rating equipments. 2. In 53 percentage of 45 diagnostic x-ray equipments, the total filtration in the useful x-ray beam was not less than the values given in the Korean industrial standard. This results suggested to user to need the more ability management of diagnostic x-ray equipments using now.