The awareness of the high-value industry for container terminal leads competitiveness of container terminals to keep high fiercely. In regards to competitive factors of container terminal, the most important point among several factors is seemed to be the speed of container loading and unloading on quayside. In container terminals in Korea, the productivity shows big difference even though its condition is similar to each terminal. The objective of this paper is to find the critical factors of container terminal productivity, which is dependant upon the capability, quantity of quay crane, transfer vehicle, and so on. For this purpose, we have researched related literatures, and collected data about container terminals in South Korea. Furthermore, we tested sensitive analysis to evaluate the extent of productivity by changing independent variable. And then we established the regression model to evaluate which factor has had the biggest impact on productivity. The results of this paper can give terminal operators guideline to improve productivity.