Abstract: In order to investigate new corn variety ‘Yudan 30’ the most suitable sowing period and the optimum planting density in Chongqing region, using split plot experiment design, to study on the relationship between sowing date and planting density on maize field of main agronomic characters and yield. The results showed that in the Chongqing area, delaying of sowing date, the fertility period was shorten, 100 grain weight and yield reduce, plant height, ear height with the sowing date delayed increase, panicle traits did not change significantly. Density increased, plant height, ear height also increased, ear length, ear diameter, stem diameter, row number, kernel number and decrease with the increase of density, 100 grain weight, yield increased with the density increasing, but to a certain threshold, increased density, yield and 100 grain weight decreased. 3 yield sowing was performance for the A1 > A2 > A3, four kind of density yield was performance as B3 > B4 > B2 > B1, sowing time and density interaction yield was performance for A1B3 > A1B4 > A2B3 > A2B4 > A3B3 > A3B4 > A2B2 > A1B1 > A2B1 > A3B1. So proper early sowing and increase planting density could increase the yield of corn per unit area, established that A1B3 was the optimum planting configuration in Chongqing area.