【Objective】To improve the tassel of maize.【Method】In this study, a cross between sweet corns inbred T4 and T19, which were significantly different in tassel primary branch number, was designed and QTLs for tassel primary branch number were identified in a whole genome with the methods of multiple interval mapping (CIM) based on 232 F₂ individuals. 【Result and conclusion】 A genetic linkage map composing of 77 simple sequence repeat (SSR) markers covering 868.7 cM with an average interval of 11.28 cM was constructed. Four QTLs for tassel primary branch number in chromosome 4, 7, 8 were detected, accounting for 5.08%-17.71% of phenotypic variance. The main QTLs were located on chromosome 8 which accounted for 17.71% of the total phenotypic variance. These QTLs provide the basis of marker-assisted selection for tassel primary branch number.