Abstract: After freezing,the photosynthesis rate and the contents of photosynthesis pigment and soluble protein of both tea the "nong kang zao"and "shi sheng cha" were investigated.It is conclusion that the quality of the "nong kang zao" is better than that of the "shi sheng cha".So,the "nong kang zao" can replace the "shi sheng cha" in the north area of Yangtze River.