An experimental investigation is performed to study the effects of embedded vortex on adiabatic film cooling effectiveness, heat transfer coefficient and heat flux ratio on a flat plate downstream of film cooling holes. A row of 11 holes, which are spaced 3 holes diameters apart in the spanwise direction, is adopted. The inclination angle of the holes is 35°. The blowing ratio is 0.5. Vortex circulation magnitude is 0.22 m 2/s at the center of film cooling hole at a mainstream velocity of 10 m/s. Four relative locations of the vortex with respect to a film cooling hole are investigated. Detailed distributions of adiabatic film cooling effectiveness and heat transfer coefficient are measured using thermochromic liquid crystal. Results show that the local adiabatic effectiveness varies remarkably as the relative position of the vortex varies. Due to relatively low blowing ratio ( M=0.5), the injectant is easily swept out so that the embedded vortex causes a dominant contribution on adiabatic film cooling effectiveness. The heat transfer coefficient distributions are greatly altered due to the secondary flow of the vortex, especially in the downwash flow region. The heat transfer coefficient is high in the downwash region of the vortex and low in the upwash region. The distributions of the heat flux ratio evaluated from the effectiveness and heat transfer coefficient show the presence of hot spots which are caused by the embedded vortex.