$Sn_XSe_{100-X}$ (15|X|30) alloys have been studied to explore their suitability as phase change materials for nonvolatile memory applications. The phase change characteristics of thin films prepared by a Radio Frequency (RF) magnetron co-sputtering system were analyzed by an X-ray diffractometer and 4-point probe measurement. A phase change static tester was also used to determine their crystallization under the pulsed laser irradiation. X-ray diffraction measurements show that the transition in sheet resistance is accompanied by crystallization. The amorphous state showed sheet resistances five orders of magnitude higher than that of the crystalline state in $Sn_XSe_{100-X}$ (x = 15, 20, 25, 30) films. In the optimum composition, the minimum time of $Sn_XSe_{100-X}$ alloys for crystallization was 160, 140, 150, and 30ns at 15mW, respectively. The crystallization temperature and the minimum time for crystallization of thin films were increased by increasing the amount of Sn, which is correlated with the activation energy for crystallization.