A field experiment following the randomized complete block (RCB) design and using Ejing 403 as material was conducted at 2 sowing dates (June 25 and July 2, respectively) and 4 seedling ages (15d, 20d, 25d and 30d, respectively) to test the effects of sowing dates and seedling ages on the yield and quality of two-season late japonica rice. The relationships of rice quality formation with the air temperature during the grain filling were also analyzed. The main purpose of this study was to establish the high- yield and high- quality cultivation techniques for the two-season late japonica rice and promote the development of “early indica- late japonica” plantation pattern in Hubei Province. The results showed that, the heading time delayed and the grain filling duration and the whole growth period prolonged, but the vegetative period in the field shortened along with the delaying sowing and prolonging seedling age. The economic yield increased at first and then decreased with the prolonging seedling age when sown on June 25, a local regular sowing date for the two-season late rice. The highest yield was attained at 20 days of seedling age and long seedling ages led to significant yield loss. Delaying sowing resulted in a significantly lower yield compared to the regular sowing time, but no significant difference in yield was detected among different seedling ages at the delaying sowing date. Both delaying sowing and prolonging seedling age lowered the grinding quality but improved the appearance quality of two-season late japonica rice. The pasting temperature of rice flour did not change much among the treatments of different sowing dates and seedling ages. However, the peak viscosity and breakdown values of rice flour at the same sowing date, as well as the final viscosity at the regular sowing date, rised at first and then fell along with the prolonging seedling ages, with the highest values being found at 20 days of seedling age. Delaying sowing resulted in consistent decreases of peak and final viscosities and the breakdown, which lowered the cooking and eating qualities of rice. Therefore, a high integrated rice qulity can also be obtained when the two-season late japonic rice is sown in the regular sowing period and transplanted with 20 days of seedling age in this region. The low air temperature during grain filling may become a limiting factor to the formation of grinding and cooking and eating qualities for the two-season late japonic rice if it heads lately.