Abstract: To improve the metering performance of the horizontal plate precision meter for corn, some key factors of the metering performance were determined. Calculation methods of the metering performance indexes by GB6973-86, Single(Precision) Seeder Experimental Method, and the statistic program developed by the Lab Windows CVI software were applied to calculate different performance indexes; and comparative experiments of the metering performance were conducted by changing the structure parameters and rotational speed of the moving plate, pusher and ejector type, as well as using different seed type in the meter test-bed and checking device of the performance test. The results show that the metering performance indexes can meet the standard of the national precision meter, by selecting cell number with 28 and cell type with the notch and small edge angle, and pusher and ejector type with ball bearing at 17 r/min rotational speed, and a moving plate thickness of 6 mm for "Nongda 108". Under these conditions, qualification index A,overlapping seeding index D and missing seeding index M is 90.71, 8.58 and 0.71, respectively, while 5 mm for "Tangyu" No.10, qualification index A,overlapping seeding index D and missing seeding index M is 91.52, 6.56 and 1.92, respectively. The results confirm that the reasonable match among the moving plate thickness, the cell type and numbers, and the seed size, together with the ball bearing pusher, can improve the metering performance of the horizontal plate precision meter.