A comparative experiment was systemarically conducted to study the response of corn to different rates of Mn application under the conditions of soilless culture, pot experiment and field trial. The results indicated that there were no significant differences in the shoot dry weight and grain yield of corn between the treatmews with Mn input rate as high as 55 mg/L (500 times higher than normal) in nutrient solution and MnSO₄·H₂O rates of 5g/kg soil in pot Gut 1500 g/m² in field trials and their respective control treatment. Also, no remarkable change in the Mn uptake by the plant as recorded when Mn concentration in nutrient solution was below 1.1mg/L and MnSO₄·H₂O races were 0.17g/kg soil or lower in pot culture and 1500g/m² in field trials as compared with CK treatments. The plant Mn content increased linearly as the medium (rockwool and pot soil) Mn content increased over the above-mentioned Mn rates, showing a characteristic passive Mn absorption of the corn.