Objective To analyze the polymorphism(s) or mutation(s) of the granulocyte colony-stim- ulating factor gene (G-CSF,Csf3) and its possible association with the susceptibility to systemic lupus erythe- matosus (SLE).Methods Polymorphism screening was carried out by the polymerase chain reaction-single strand conformation polymorphism method (PCR-SSCP),using DNA from 204 Northern Chinese patients with SLE,459 ethnically matched healthy control,78 patients with other autoimmune diseases.Results It was i- dentified that 4 polymorphisms at position 1869,1205,1931,and 394.The nucleotide sequences of the sample that showed different SSCP patterns and different distribution between SLE and healthy controls were deter- mined by direct sequencing.Only the distribution of the fifth extron of Csf3 (1931) between SLE and controls was different.The frequency of A/G genotype (60.5%) and A allele (53.2%) at position 1931 in patients with SLE was significantly higher than that in healthy controls (51.6% and 45.2%,respectively),whereas,the fre- quency of G/G genotype (16.2%) and G allele (46.8%) in patients with SLE was lower than that in healthy controls (28.9% and 54.8% respectively).Conclusion The results suggest that Csf3 (1931) is significantly associated with the susceptibility to SLE in Northern Chinese patients .Further population and functional stud- ies will be followed to establish Csf3 (1931) as one of the susceptible genes for SLE.