Abstract: Objective：To investigate the clinical significance of BRAF gene mutation detection in colorectal cancer. Methods：The BRAF gene mutations in paraffin embedded tumor tissues of colorectal cancer patients were detected by PCR direct sequencing, and the relationship between BRAF gene mutation and gender, age, histological grade, and clinical stage was analyzed. Results：In 17 cases of colorectal cancer with BRAF gene mutations, 16 cases had mutations in fifteenth exon and 1 case in eleventh exon. In 16 cases, mutations were mainly located in the 600th codon of the fifteenth exon in 14 cases, including 13 cases with the 1 799th base mutation of T to A (Val600Glu, V600E; accounting for 92.9% of the mutations in the 600th codon), and 1 case with the 1 799th and 1 800th base mutations of GT to AA (Val600Glu, V600E); 2 cases in the 594th codon of fifteenth exon with the 1 780th base G to A (Asp594Asn, D594N). The mutation of eleventh exon in 1 case was in the 468th codon with the mutation of the 1 403rd base G to C (Gly468Va, G468V). The status of BRAF gene mutations was not related to the sex and age of the patient. The number of BRAF gene mutation patients with histological grade Ⅲ was more than that of grade Ⅱ(P=0.029) and the number of BRAF gene mutations with clinical stage Ⅳ was more than those with stage Ⅱ and stage Ⅲ(P=0.011). Conclusions：BRAF gene mutations in colorectal cancers are associated with histological grade, clinical stage and worse prognosis. With the increase of histological grade and clinical stage, the mutation rate of BRAF gene increases.