Objective: To study the effect of sevofluranein on the developmental hippocampal neurons of rats and the possible mechanism. Methods: Hippocampal neurons were harvested from within 24 h-old Sprague-Dawley rats and cultured in the different media. Then Hippocampal neurons were randomly divided into 4 groups and treated with air (control group, CG), sevofluranein (1 minimum alveolar concentration) for 3 h (S3 group), 6 h (S6 group), 12 h (S12 group) respectively. Average neurite length and mean optical density (MOD) were used as statistical indexed and detected. Proliferation was quantified by flow cytometry. BDNF and TrkB protein expression were assessed by Western blot. Results: Average neurite length and MOD showed the same result between S3 group and CG (P>0.05), while the opposite result appeared in S6 group and S12 group (P<0.05). S6 group decreased with significant difference compared with S3 group and S12 group (P<0.05). Compared with CG and S3 group, neuronal apoptosis rate in S6 group and S12 group increased (P<0.05). BDNF and TrkB protein expression in S6 group and S12 group was lower than those in CG, while that in S3 group was higher (P<0.05) and gray value had the same result. Conclusion: The effect of sevoflurane on hippocampal neurons in vitro is bidirectional which may be related to the time through the BDNF-TrkB pathway.