Productivity of rainfed cotton in shallow and marginal soils can be improved by high density planting of early maturing varieties. The mandatory requirements of high density cotton planting system are seed singulation and placement of single seed at desired depth. Inclined plate seed metering mechanism was selected for developing the prototype. Four levels of peripheral velocity of the inclined plate (0.10, 0.15, 0.20 and 0.25 m s-1), five levels of angle of inclination of seed plate with horizontal (40, 45, 50, 55 and 60 deg.), 3 levels of cell size (8.5, 9.4, 10.7 mm) and 3 levels of forward speed (1.5, 2.0 and 2.5 km h-1) were selected for the laboratory test conducted in a test rig having grease coated conveyor belt to measure the single seed metering index(SSMI). The highest SSMI value of 84.9 per cent was obtained at 0.20 ms-1 peripheral velocity of the seed plate, 550 inclination of seed metering disc with horizontal, 8.5mm cell size and at 1.5 km h-1 forward speed of operation of the planter.