Our previous study demonstrated that the Korean traditional medicine Gyeongshingangjeehwan (GGEx) inhibits obesity and insulin resistance in obese type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. We investigated whether GGEx may affect AMP-activated protein kinase ${alpha}$ ($AMPK{alpha}$) since $AMPK{alpha}$ activation is known to stimulate fatty acid oxidation in skeletal muscle of obese rodents. After OLETF rats were treated with GGEx, we studied the effects of GGEx on $AMPK{alpha}$ and acetyl-CoA carboxylase (ACC) phosphorylation, and the expression of $AMPK{alpha}$, $PPAR{alpha}$, and $PPAR{alpha}$ target genes. The effects of GGEx on mRNA expression of the above genes were also measured in C2C12 skeletal muscle cells. Administration of GGEx to OLETF rats for 8 weeks increased phosphorylation of $AMPK{alpha}$ and ACC in skeletal muscle. GGEx also elevated skeletal muscle mRNA levels of $AMPK{alpha}1$ and $AMPK{alpha}2$ as well as $PPAR{alpha}$ and its target genes. Consistent with the in vivo data, similar activation of genes was observed in GGEx-treated C2C12 cells. These results suggest that GGEx stimulates skeletal muscle $AMPK{alpha}$ and $PPAR{alpha}$ activation, leading to alleviation of obesity and related disorders.