Insulator-to-metal phase transition (PT) and relaxation dynamics in VO2 were studied with ultrafast transient reflection spectroscopy and degenerate four wave mixing technique. Optical pumping of free carriers in VO2 initiates PT on a femtosecond time scale. The relaxation dynamics is strongly dependent on pump energy. Spectral reflectivity behaviour at PT due to thermal heating and upon laser excitation of VO2 demonstrates close proximity in the relative change. PT induced by light was interpreted by exciton-controlled mechanism. Excited state dynamics of metallic VO2 is assigned to formations of electronic and hole polaronic states.