Complete diallel cross was carried out using five special-early mature Gossypium hirsutum L. varieties, Parental, F1, F2 as three generations were experimentally investigated. The results showed that: seed cotton yield, lint yield, number of bolls per plant existed significant dominant effects, additive effects were second. Boll weight existed significant additive effects, dominant effects were second. Lint percentage existed significant dominant effects and weak epistatic effects, no additive effect. Early maturity traits such as growth period, flowering rate before frost and boll stage existed significant additive effects, dominant effects were second. The average fiber length of upper half, breaking strength, micronaire, elongation, spinning evenly index, reflectivity, and other quality traits existed significant additive effects, dominance effects and epistatic effects were smaller or nonexistent. Environmental factors had very significant effects on the yield, earliness and fiber quality traits. Genetic and phenotypic correlation analysis showed that there were a (very) significant positive correlation among seed cotton yield and lint yield with number of bolls per plant, lint percentage and flowering rate before frost, a (very) significant negative correlation with boll weight and growth period. There were a (very) significant positive correlation among the average fiber length of upper half, breaking strength and spinning uniform index and a (very) significant negative correlation with micronaire and flowering rate before frost, a (very) significant positive correlation with other early maturing traits and seed cotton yield and lint yield. There were a (very) significant negative correlation between micronaire value and yield and early maturing traits.