Objective To investigate the relationship between ABCB1 gene polymorphism and the changes of body weight， blood glucose and blood lipids after olanzapine treatment in patients with schizophrenia. Methods A total of 72 patients with schizophrenia were prospectively enrolled in the study group from July 2017 to December 2018， who were treated with olanzapine alone. The rs1045642 and rs2032582 polymorphisms of ABCB1 gene were genotyped by Taqman probe genotyping technique. Repeated measurement analysis of variance was used to compare the changes of body weight， blood glucose， total cholesterol， triglyceride， high density lipoprotein（ HDL） and low density lipoprotein between different genotypes of ABCB1 gene rs1045642 and rs2032582 at baseline and 8 weeks after treatment. Results （1） Repeated measurement analysis of variance results showed that CC genotype of rs1045642 locus had significant difference in weight gain and decrease of fasting blood glucose before and after treatment， which was statistically significant［ （62.76±9.42）kg vs（ 58.95±12.03）kg， t=10.040， P ＜ 0.05；（ 5.08±1.28）mmol/L vs（ 6.33±2.38） mmol/L， t=7.268， P ＜ 0.05］， but differences in CT and TT genotypes before and after treatment（ All P＞0.05） were not statistically significant. After treatment， the HDL of CC and TT genotypes of rs1045642 decreased compared with those at baseline［ 1.12±0.30） mmol/L vs（ 1.31±0.57） mmol/L， t=6.530， P＜ 0.05；（ 1.36±0.23） mmol/L vs（ 1.54± 0.19） mmol/L， t=10.161， P ＜ 0.05］， which were both statistically significant. However， differences between before and after CT genotype treatment（ P ＞ 0.05） were not statistically significant.（ 2） Single effect analysis showed that compare with baseline GG and TT genotypes of rs2032582 locus both had weight gain after treatment ［（62.57±0.61）kg vs（ 59.23±12.20）kg， t=6.159， P ＜ 0.05；（ 60.19±6.93）kg vs（ 57.31±8.97）kg， t=5.188， P＜ 0.05］， which were statistically significant. But differences in GT genotypes before and after treatment were not statistically significant（ P＞0.05）. Compare with baseline， blood glucose and HDL in GG genotypes decreased after treatment［ （5.19±1.39）mmol/L vs（ 6.44±2.56）mmol/L， t=5.220， P ＜ 0.05；（1.18±0.30）mmol/L vs（ 1.36±0.58）mmol/L， t=5.576， P ＜ 0.05］， which were statistically significant. But those of GT and TT genotypes were not statistically significant before and after treatment（ all P ＞ 0.05）. Conclusions ABCB1 gene polymorphism may be associated with weight gain and abnormal blood lipid metabolism after olanzapine treatment.