This paper studies the variable load ratio characteristics by experimental methods for the multi-spilt air-conditioning system K-1, which is installed in school of Environmental and Municipal Engineering of Xi’an University of Architecture and Technology. The temperature changes along with the refrigerant liquid pipe were tested under different partial load ratio conditions in summer. Experimental results demonstrate that the liquid refrigerant temperature for outdoor unit at outlet increased with the increment of the load ratio. On different load ratio conditions, the liquid refrigerant temperature decreased rapidly along refrigerant vertical pipe and turned to change slowly along horizontal pipe. When load rate is between 50% and 80%, energy efficiency ratio (EER) value is relatively high, about 2.63~2.84. EER value reaches a maximum of 2.84 with 65% load ratio.