AIM: To investigate the relationship between 5-hydroxytryptamine transporter (5-HTT) gene polymorphism and plasma 5-hydroxytryptamine (5-HT) lever, clinical response of selective serotonin reuptacke inhibitors (SS-RIs) in Chinese depressive patients. METHODS: Polymerase chain reaction (PCR) was used to detect the polymorphism of 5-HTT gene in 132 depressive patients and 100 controls. HPLC-electrical chemistry detector method was used to analyse plasma 5-HT lever. The depressive states were assessed with Hamilton Depression Rating Scale (HAMD). RESULTS: There were no significant differences of the 5-HTT polymorphism genotypes and alleles between 132 depressive patients (LL24.2%, LS44.7%, 3531.1%; L46.59%, 853.41%) and 100 controls (LL29.0%, 1547.0%, SS 24.0% ; L 52.5 % , S 47.5%), P > 0.05. The HAMD and plasma 5-HT lever of pre-treatment were significant differences in depressive patients with different 5-HTT genotype (F = 6.48, P = 0.002 1; F = 5.38, P =0.005 7). The HAMD reductive date and plasma 5-HT lever increasing date of 4 wk SSRIs post treatment were significant differences in depressive patients with different 5-HTT genotype ( F = 3.38, P < 0.01; F = 23.55, P < 0.01). CONCLUSION: The 5-HTT polymorphism is not associated with depression, but is associated with disease serious degree and SSRIs clini- cal responses in Chinese.