Abstract: NCⅡdesign was made by using 4 early-maturation varieties as material parents, 6 late-maturation varieties as paternal parents, the results showed that the development days and speed of the early-maturation varieties were shorter and faster than the late-maturation varieties from emergency to squaring and from flourishing flowering to ending flowering, but the development days, viz. filling days longer than the late-maturation varieties, it was an important physiological reason which resulted in the high yeild in the early-maturation varieties; the squaring time was an important indicative character of sesame earliness, which no direct relationship existed between beginning flowering and ripening; the development days of different stage was restricted each other in one growth period.

Key words: Sesamum indicum L., Growth period, Earliness, Coefficient of correlation, Heritability