ObjectiveTo explore the possible mechanism of Jianpi Huazhuo Tiaozhi Granule （健脾化浊调脂颗粒， JHTG） in treating atherosclerosis （AS） based on the regulation of perivascular adipose tissue （PVAT） browning via the phosphoinositide 3-kinase/protein kinase B （PI3K/AKT） signaling pathway. MethodsFifteen SPF male C57BL/6J mice served as control group， while 76 ApoE^-/- mice were first fed a high-fat diet for 16 weeks to establish AS model. After successful modeling， they were randomly divided into model group （n=16）， as well as the browning group， the low-， medium- and high-dose JHTG group， with 15 mice in each group. The browning group was intraperitoneally injected with β3-adrenergic receptor agonist CL 316243 at 1 mg/（kg·d） once daily. The low-， medium- and high-dose JHTG groups were treated with 4.3 g/（kg·d）， 8.6 g/（kg·d）， and 17.2 g/（kg·d） of JHTG by gavage， respectively， while the control group and the model group were given normal saline at 10 ml/（kg·d） by intragastric administration， once daily. All groups received continuous intervention for 4 weeks. The aorta was collected to assess the plaque ratio by gross oil red O staining. HE staining was used to measure the plaque area in cross-sections. Masson staining was employed to detect the proportion of collagen fibers in plaque. Transmission electron microscopy was used to observe the quantity and morphological changes of mitochondria and lipid droplets in adipocytes. The levels of serum triglycerides （TG）， total cholesterol （TC）， high-density lipoprotein cholesterol （HDL-C）， and low-density lipoprotein cholesterol （LDL-C） were detected， as well as tumor necrosis factor α （TNF-α） and interleukin 6 （IL-6） levels in the PVAT and aorta. The protein levels of adiponectin and leptin in PVAT， and protein expression levels of phosphoinositide 3-kinase （PI3K）， phosphorylated phosphoinositide 3-kinase （p-PI3K）， protein kinase B （AKT）， phosphorylated protein kinase B （p-AKT）， uncoupling protein 1 （UCP1）， peroxisome proliferator-activated receptor γ coactivator 1α （PGC-1α）， and PR domain containing 16 （PRDM16） were measured. The mRNA expression levels of UCP1， PGC-1α and PRDM16 in PVAT were detected. ResultsCompared to the control group， the model group showed increased serum TG， TC， and LDL-C levels and decreased HDL-C level， elevated TNF-α and IL-6 levels in PVAT and aorta， decreased average fluorescence intensity of adiponectin， increased average fluorescence intensity of leptin， reduced p-PI3K/PI3K and p-AKT/AKT values as well as protein levels and mRNA expression levels of UCP1， PGC-1α and PRDM16 （P＜0.01）. The pathological results showed that no significant plaque formation was observed in the aortas of mice in the control group. In the model group， multiple plaques were observed in the aortas， with large numbers of foam cells， cholesterol crystals， and inflammatory cell aggregation in the plaques. Compared to the model group， the browning group and the high-dose JHTG group significantly improved the above indicators and aortic pathological changes （P＜0.05 or P＜0.01）. Three JHTG groups showed a dose-dependent effect in reducing LDL-C level and plaque ratio by gross oil red O staining， elevating the average fluorescence intensity of adiponectin， the p-AKT/AKT value， the protein level of PGC-1α， and the mRNA expression levels of UCP1 and PRDM16 （P＜0.05）. The high-dose JHTG group and the browning group showed similar efficacy in improving the pathology of the aorta. ConclusionJHTG may promote PVAT browning in AS model mice through the PI3K/AKT pathway， improve the endocrine function of PVAT， inhibit aortic inflammation， and thereby ameliorate the formation of AS plaques.