Low-power laser irradiation (LPLI) can promote cell proliferation, migration and differentiation through activation of multiple signaling pathways. However, it is unclear whether LPLI can promote triglyceride biosynthesis in adipocytes via regulation of extracellular signal-regulated kinase (ERK) and protein kinase B (PKB, also named Akt). In the present study, the changes of the ERK and Akt activity in 3T3-L1 pre-adipocytes and mature adipocytes upon LPLI stimulations is investigated using western blot analysis. The findings indicate that the activity of ERK and Akt is significantly elevated in 3T3-L1 pre-adipocytes under LPLI treatment. In contrast, the activity of ERK is dramatically reduced in mature adipocytes, but the activity of Akt is significantly elevated under LPLI treatment, suggesting that LPLI can differentially regulate the activity of ERK and Akt. Furthermore, the concentration of triglyceride in insulin resistant adipocytes is increased which is induced by LPLI through inhibition of ERK and activation of Akt. These results imply that LPLI can improve lipid metabolic disorders-induced insulin resistance through regulation of ERK and Akt.