Super high yielding rice cultivars were studied to understand their growth characteristics. These cultivars showed high biomass production, leading to increased grain yield. The main factor contributing to grain yield was biomass production, rather than harvest index. The growth rate of the rice plants during the middle and late stages had a strong positive correlation with yield. Stem and leaf dry matter exportation significantly contributed to grain production. Overall, the crop growth rate played a larger role in dry matter accumulation than growth duration.