In many varieties of rice, the length of basal pores on the thecae just after anthesis is strongly correlated both with the percentage of florets receiving adequate pollen and with the number of pollen grains deposited on the stigmata and its variation (coefficient of variation). Therefore, the size of the basal pores is considered to be an important factor for the reliable self-pollination of rice. We discuss how long basal pores may facilitate self- pollination.