The account deals with the effect of photo-function (a term to indicate the variable sensitivity to photoperiod of a shoot during growth) of transplanted rice. VarietiesTKM. 6 andADT. 20 were used as test crops. Post-planting photo-function is controlled by age of seedling. Post-planting effect is varietal and continuous on the life of the plant. The sub-optimal sensitivity of the plant to light increases with the age of the seedling and suppresses growth and development of the early shoots remarkably. It is recommended that by choosing the age of the seedling for planting, the plant can be adapted to a dull or bright weather ahead and younger the seedling, better the response to day length.