Abstract: Abstract:In order to innovate maize breeding new materials, gradient tropical germplasm populations were constructed according to different proportion of tropical germplasm into temperate germplasm. Using Gradient tropical germplasm populations as test materials, explored the traits genetic potential and difference. The result shown that plant height (pH) and ear height (EH) genetic difference between gradient populations were significant. Gradient populations of plant height and ear height from 100% tropical germplasm low to 50% tropical germplasm, showing a gradually increasing trend, but not the magnitude of changes.When the proportion of tropical germplasm down to 25% and 12.5%, plant height and ear height significantly reduced.