Crop forecasting through anticipation of future weather pattern and timely decision of proper agricultural management practices to avoid sudden crop failure is one of the advanced ways of sustainable agriculture. Crop growth simulation model can be successfully used to asses the yield under changing climatic condition which may be useful for developing adaptation and mitigation measures. Considering the fact, an attempt has been made to predict the future yield of rice in plane region of Chhattisgarh using Decision Support System for Agrotechnology Transfer (DSSAT v 4.5). Management combinations simulated were three sowing dates 11th June, 21th June and 29th June in 2011 and 10th June, 15th June and 22nd June in 2012 for wet season rice cv. Karmamasuri under rainfed and irrigation condition. Thirty three year (1981-2012) weather data (Max T, Min T, Rainfall and Radiation) was collected from IGKV, Raipur. First, the DSSAT v4.5 model was calibrated and validated for locally popular medium duration variety Karmamasuri for wet season (2011-2012). The result showed that the early and late sowing dates gave lower yield as compared to optimum sowing dates. The weighted yield was observed more than actual yield in central Chhattisgarh.