Abstract:The objective of this research was to select the best photoperiod that improves Crocus sativus flower and stigma quality. In this study, the growth characteristics, flower characteristics, saffron stigma quality and value were determined with three weights of saffron corm (20-25 g, 25-30 g, 30-35 g per corm) under 8 h/16 h, 10 h/14 h, 12 h/12 h, 14 h/10 h four photoperiod treatments. Results showed that: (1) 8 h/16 h treatment obviously accelerated apical bud height growth, increased the number of corms with exposed leaves. (2) It had larger flower diameters, increased flower quantities, advanced flowering time in first five days with 8 h/16 h and 12 h/12 h photoperiods. (3) There was no significantly different in stigma crocin, stigma dried weight, stigma fresh weight, the percentage of stigma dry weight on fresh flower weight and water contents under different photoperiods. (4) The contents of soluble sugar, starch, soluble protein increased in 8 h/16 h and 10 h/14 h photoperiods, and decreased in 12 h/12 h and 14 h/10 h treatments. In conclusion, our results indicated that 8/16 h photoperiod was the best for the saffron which benefits to saffron growth and advanced flowering time in early flowering period. However, there was no significant effect on saffron stigma value with different photoperiods.