Nutrients behavior were investigated at a paddy fields area(50ro-ri) with large-scaled plots on loam soil during irrigation seasons of 2001~2002. The average concentration of TN, TON and TOP in drainage water was higher than that in irrigation water. On the other hand, TP in irrigation water was higher than that in drainage water. The ratio of a TON to TN accounts for over 90% and the ratio of TOP to TP accounts for 50~70%. Especially, the ratio of TOP to TP in drainage water was bigger than that in irrigation water, suggesting that much of particulate component was reduced due to sedimentation and adsorption in paddy fields plots.