Studies were undertaken to develop a coating system for popcorn in order to achieve maximum number of popped kernels during microwave heating. The effects of microwave power levels and different ingredients (hydrogenated oil, sodium chloride, butter, sodium bicarbonate) on popping behaviour of popcorn during microwave heating were studied using a central composite design. All the regression models were significant at the p < 0.025 level and showed R-2 value in the range of 89-92%. The models developed can be used as a tool to study popping behaviour of popcorn. Popcorn having more than 75% of popped kernels and lower than 0.05 g/cm(3) of bulk density can be achieved using 10% hydrogenated oil, 2% butter and 0.5% sodium chloride and heating popcorns at 70% power in a microwave oven with a magnetron having actual power output of 660 W and operating frequency of 2450 MHz.