Abstract: DUS testing is to test the distinctness, uniformity and stability of a new species, which is a necessary foundation of whether the new species is granted being protected. The result of the DUS testing influences whether a new variety should be protected. Quantitative character is the significant part of describing the character of species in DUS testing, however, investigation of quantitative character is a manpower demanding work, so it has become a important topic DUS testing workers facing with about how to deflate the manpower at the same time reflecting the accuracy of quantitative character. this is the main purpose of this paper.Nowadays, it demands 40 samples for one quantitative character by national maize guideline. In our experiment, we have a significance analysis for 40 data, aiming at 10 testing samples,10 quantitative character, the minimum of testing samples for DUS testing depends on the theory of sampling distributing and scope estimating.