Carnitine palmitoyl transferase 1b (CPT1b) and Myogenin are important markers of metabolism and myogenesis, respectively. The present study aimed to research the expression of CPT1b and Myogenin mRNAs in skeletal muscle C2C12 cells incubated with obese factors, free fatty acid (FFA), or lipopolysaccharide (LPS), to support the mechanism related to obesity and metabolic disorders. The result indicated that FFA significantly induced upregulation of CPT1b and Myogenin mRNAs in the skeletal muscle cells. In contrast, LPS treatment did not affect on expression of CPT1 mRNA and tendency reduced expression of Myogenin mRNA in the skeletal muscle cells. These data support the evidence FFA is an energy and nutrient source for metabolism and myogenesis in the skeletal muscle cells whereas LPS seemingly suppresses myogenesis. Therefore, the mechanisms linking FFA or LPS to obesity induced skeletal muscle metabolic dysfunctions could be different.