The objective of this article is to suggest enhancement strategies for the %PSE(Percentage PSE) developed by OECD. The %PSE is supposed to measure the ratio of market/government support for the agricultural producers to total value of production. However, there have been many criticisms on what it actually measures and how it is measured, even though it is one of the most frequently quoted measures of support for agricultural producers. In this paper, major shortcomings of PSE and %PSE are discussed and the current procedure to compute %PSE is analysed to see if the procedure secures an exact measure of the support, focusing on Korean case. The 4 major concerns associated with %PSE are; setting an appropriate reference price, consideration of quality difference, the sensitiveness of %PSE to the share of standard commodities, and classification of budgetary payment. An appropriate reference price for rice alone would make the overall %PSE of Korea fall by 0.5-1% point. Introducing a quality coefficient for rice may cause the overall %PSE drop by 9-10% points. Introducing more standard commodities may decrease the overall %PSE by 4-6% points. The impact of the new classification of budgetary payment proposed by OECD is not quantified but expected to be small. However, cautionary approach is called for and reasons are proposed.