〔Abstract〕 Objective To evaluate the therapeutic value of JTE-907(cannabinoid CB2 receptor reverse agonists) in a model of neutrophilic asthma, and to determine the potential therapeutic mechanism of CB2 receptor activation by observing its effect on the differentiation of CD4+na6 ve T cells. Methods In order to study the effect of JTE907 on the differentiation of T cell subtypes, used anin vitrosystem of Th lineage-specific differentiation of na6 ve CD4+T lymphocytes isolated from the rat spleen. The expression of Tbx21, Gata3, interleukin(IL)-9, ROR-C, FoxP3, CNR2 mRNA was detected by qRT-PCR. 40 rats were divided randomly into four experimental groups with 10 animals each: normal control group, model group, JTE-907 low-dose group(JTE-907-L, intraperitoneal injection of 5 mg/kg) and JTE-907 high Dose group(JTE-907-H, 20 mg/kg). Except for the normal control group, rats at other three groups were established neutrophil asthma models. The concentration of serum OVA-specific IgE and BALF cytokine was detected by ELISA. The percentage of Th17 and Treg cells in spleen was analyzed by flow cytometry, and the expression of RORγt, Foxp3 and STAT5 protein in lung tissue was detected by Western blot. Results qRT-PCR analysis showed that JTE907 induced the expression of FoxP3 and CB2 receptors at all the concentrations tested. After OVA sensitization and LPS stimulation, the level of OVA-sIgE in the model group increased(P<0.05), and the number of neutrophils and the levels of interferon(IFN)-γ, tumor necrosis factors(TNF)-α, IL-17 and IL-5 in BALF significant increased(P<0.05). JTE-907 treatment significantly reversed the above changes(P<0.05). In addition, compared with the model group, the ratio of Th17/Treg in spleen of JTE-907 treatment group significantly decreased(P<0.05), and the level of RORγt protein in lung tissue significantly decreased(P<0.05), while the levels of Foxp3 and p-STAT5 significantly increased(P<0.05). Conclusion The activation of CB2 receptor has a protective effect in rat with Th-17 mediated neutrophilic asthma. The mechanism of JTE907 effect involves improving Th17/Treg balance, as well as regulating their respective cytokine levels.