By suggesting short and mid term milk supply response models composed of number of milking cow and yield per cow functions, this paper aims to estimate price elasticites of milk supply with respect to milk, feed and beef prices. Estimation results show the price elasticity with respect to feed price is largest for both short and mid terms. The coefficients on beef price in the number of milking cow and the yield per cow functions are pretty significant. This result suggests that beef market must be considered when we design a dairy policy for milk supply control. The dummy variables in the supply response model presents the policies that were implemented for reducing excess stock of milk during 2002~2003 have contributed an additional supply of milk.