Abstract: The tillering angle was an important plant type trait of rice, and the suitable tillering angle was the key factor to achieve the high yield of rice. The specific molecular marker S-TAC1 based on STARP (Semi-thermal asymmetric reverse PCR) technology was designed for the functional site of TAC1, which was the major efficiency gene controlling the tillering angle of rice, and the genotype identification of 56 sequenced conventional rice varieties and 164 hybrid rice varieties were conducted. S-TAC1 accurately identified the genotypes of 56 sequenced conventional varieties, including 36 compact homozygous genotypes tac1/tac1 and 20 incompact homozygous genotypes TAC1/TAC1, which indicated that the S-TAC1 typing results were accurate and reliable. Among 164 hybrid rice varieties, 62 were heterozygous genotypes TAC1/tac1 and 102 were incompact homozygous genotypes TAC1/TAC1. The functional markers developed in this study provided technical support for the cultivation of rice varieties with ideal plant type by molecular marker-assisted selection.