Copper has been recogn ized as one of the most limiti ng m i cronutrien ts in many crops groiun on tropi ca I pea t. Th is stu dy was conducted to determine the effects of copper and lime interaction on the growth of sweet corn fZea mays L. var. Thai Supersweet). An undisturbed peat sample was taken at a depth of 0-20 cm. The moist peat xuas then thoroughly mixed and placed in plastic pots which xoere treated with 5 rates of copper sulphate (at equivalent rates ofO, 5, 10, 15 and 20 kg Cu ha~ ) and 4 rates of dolomitic limestone (0,2,4 and 101 lime ha~ ). Application of copper at the rate of 5 kg Cu ha" and4tGMLha~ gives optimum dry matter yield. Addition of copper at a rate of more than 16 kg Cu ha-1 reduces the uptake of copper by corn at all rates of lime. The results also indicate that peat soil containing less than 8. 7flgg~ DTP A extractable copperrequires copperfertilization. The minimum peat soil pHthat gives themaxium accumulated corn dry matter yield is 4.40. This study suggests that tropical peat requires liming and copper fertilization and that these inputs have synergistic effects on thegroxvth ofsxveet corn.