Abstract: [Objective] To study the genetic law of short-season cotton growth period.[Method]Our study utilized four upland cotton cultivars to construct two crosses and analyzed three traits(Flowering time FT,Flowering and boll-setting period FBP,Whole growing period WGP)of growth period using the joint segregation analysis method of mixed major gene plus polygene inheritance model.[Result]The results from phenotypic analysis showed that: the other phenotypic traits were in favor of the early-maturing parent and the partial early-maturing parent,except for the combination of F1 in the blooming stage and F2 sowing-flowering stage.The genetic analysis results showed that: the same traits of the combination I and II were in accordance with the same genetic model,and were controlled by two pairs of major genes.[Conclusion]It can be seen from the heritability of major genes and polygenes,the three phenotypic traits were mainly controlled by the major genes and the minor genes,the heritability of the three phenotypic traits is high,and the additive effect is large.This study could provide a theoretical basis for QTL mapping and molecular marker assisted breeding of cotton early maturing traits.