As basic study on effects of the decasualization of port labor, this paper watched labor supply framework reorganization, focused on port worker in Incheon port at before decasualization(2005~2007.9) and after decasualization(2007.10~2010.5) and analyzed disposal quantity, workers, workdays, productivity, accident and disaster data that was apt to influence by the decasualization of port labor. Though commercial traffic of Incheon port was decreased in global economic depression, individual workday per month after decasualization compared with before decasualization is decreased by 3.3days from 22.7day to 19.4days, on the other hand, indivisual annual loading and unloading throughput is increased averagely 71.6%, and labour productivity, when 2005 labour productivity are 100, are increased by 67%. After decasualization, overall loading and unloading productivity is improved. But, according to loading and unloading, the number of accident and disaster are increase by 11.7% after decasualization for loading and unloading operation.