A new method to actuate a small droplet on a plate is proposed. A laser beam is irradiated on one end of the droplet set on a SAMs (Self-Assembled Monolayers) plate. Since the wettability at the heated side is improved remarkably, the tangential component of surface tension pulls the droplet toward the spot of laser beam. In this report, the resultant force in the tangential direction is estimated experimentally when the droplet starts to slide on the plate. In order to obtain the temperature dependence of contact angles, the axi-symmetric droplet profile is measured while irradiating the laser beam homogeneously over the droplet. The temperature is estimated from the surface tension determined from the comparison between the solution of Laplace equation and experimental droplet profile. Based on the measured temperature dependence of contact angles, the resultant of surface tension acting on the circumference of droplet is calculated at both ends of droplet when the laser beam is irradiated on the one end. The calculated results show that the resultant force is actually positive and rapidly increases when the droplet starts to slide.