Brassica napus L. (Brassicaceae), is one of major oilseed crops commonly cultivated cereal-growing areas after the rice harvest in Asia countries, has recently focused much attention as its seed is the primary source for bio-diesels. In rapeseed growing regions of South Korea, typical double-cropping regions are constantly or periodically received with poorly drained soil condition or encountered dried soil condition during the reproductive stage. This study was conducted on rapeseed plants subjected to both waterlogging and drought conditions for 4 days to investigate responses in physiological characteristics, fatty acid compositions and yield performances at reproductive stage. The treatments were thus as follows: (1) control normally irrigated, (2) waterlogging treatment were flooded by placing their pots inside larger plastic pots filled with tap water with a 2-cm water layer over soil surface, (3) drought treatment was not irrigated. For recovery period, rapeseed plants subjected to waterlogging for 4 days were drained after waterlogging, and irrigated daily as control. Drought treatment after recovery period was irrigated daily as control. Rate of photosynthesis and stomatal conductance of waterlogging and drought treated plants significantly decreased within 4 days. For recovery period, stomatal conductance and photosynthetic rate of the waterlogged and drought treated plants occurred level similar to that of the controls by 2 days after recovery period. Fatty acid compositions of the both waterlogging and drought treated plants did not affect, but yield performances of the waterlogging treatment significantly decreased. These results suggest that both waterlogging and drought conditions for 4 days did not influence fatty acid compositions, but affected yield performance at final harvest.