Test of mechanical performance to hydraulic mass concrete is still in the presence of wet-screened tests from small-scaled samples. But, wet-screened tests of concrete is often picked out large aggregates above 40mm. Test results from wet-screened concrete’s samples must different from it’s full-graded tests and not exactly reflect mechanical performance of dam’s concrete. Based on demand of concrete’s design strength of Jinping I Arch Dam, lots of full-graded tests from uniaxial compression, tension, limit tension and elastic modular were completed. Dam concrete’s uniaxial tension strength ratio between full-graded and wet-screened tests of 180d age fluctuates to 0.661, 0.637 and 0.690 for design strength of C180 40、C180 35、C180 30. Similarly, its limit tension strains ratio of 90d age is 0.583, 0.579 and 0.573. Under the influence of large aggregates, the elastic modular from full-graded tests is above it from its wet-screened tests.