In South Korea, the rice farming is known to be well prepared for climate change impacts because the irrigation infrastructure of rice fields is well established. However, a rice yield forecasting model from previous research shows that rice quality can be decreased in extreme weather conditions, even for an irrigated rice paddy field. In addition, change in the rice growth duration has a critical role in reducing rice quality and quantity, respectively. In a simulation analysis with two climate change scenarios, this paper highlights a decrease in average rice productivity; the expected reduction of rice productivity is -6.96% (RCP 4.5), -14% (RCP 8.5) in the third stage (2071-2100) compared to the reference (2001-2010). Moreover, this paper discusses the economic effects of rice planting date management as a climate change adaptation measure.The estimated results show that the rice quality tends to improve when the planting date is delayed, and the rice quantity is likely increased when the planting date is moved forward. This implies a simple but essential non-structural adaptation measure needs to be further investigated reflecting climate change-related issues such as regional heterogeneity of climate change, the difference in rice cultivar, and regional policy for rice quality and quantity.