The aim of this study is to investigate the mechanism of anti-obesity effects of Aloe vera gel extract (AVGE) containing Aloe sterols. Previously, we reported that oral intake of Aloe vera components has an anti-diabetic and anti-obesity effect. This study was designed to assess the role of brown adipose tissue (BAT) in the anti-obesity effect of AVGE. Six-week-old male mice were divided into three groups; STD (standard diet), HFD (60% high fat diet) and AVGE (60% high fat diet with AVGE treatment). During 11 wk of AVGE administration, body weight has been monitored. Tissue samples were obtained to be measured the weight and evaluated the gene expressions. Mice treated with AVGE had suppressed body weight, and liver and fat weight gain. To investigate BAT activation, we measured the expression of mRNA related to BAT thermogenesis. Mice in the AVGE group had higher expression of Ucp1, Adrb3, and Cidea in BAT compared to HFD. Next, to investigate the possibility that AVGE induced hepatic FGF21, which is an important factor for nutrient and energy homeostasis including BAT regulation, in vitro study was conducted. HepG2 cell stimulated by AVGE were highly expressed FGF21. These results suggested that BAT activation partially contributes to mechanism of anti-obesity effect of Aloe sterols in diet-induced obesity (DIO) models. However, further study is needed to determine the predominant mechanism.