Abstract:With four species of azalea as materials,we studied the growth and physiological indexes under pH 4.5,5.5,6.5,7.5,8.5 irrigation water,in order to analysis the growth conditions with different acidity and alkalinity irrigation water.The results showed that:(1)With the pH increasing,the chlorophyll contents,superoxide dismutase activities,catalase activities and new shoot growth rates of four species increased firstly and then decreased,while the relative conductivities were contrary;(2)Under pH 5.5,the chlorophyll contents of ‘Mevrouw.A’,‘Fugeer No.1’ and ‘Green Glow’,the CAT activities of ‘Mevrouw.A’,‘Spring Dance’ and ‘Green Glow’ were maximum.The same to SOD activities and new shoot growth rates of the four species,while the chlorophyll content of ‘Spring Dance’ with pH 4.5 treatment were maximum.The same to CAT activity of ‘Fugeer No.1’.Under pH 8.5,all relative conductivities were maximum,while the other indexes were contrary;(3)With pH 4.5～5.5,the cultivation matrix which initial pH value was about 5.0 could be maintained in the optimum pH range，about 5.0.Therefore,azalea can grow well with the irrigation water of pH 4.5～5.5 in the Southwest,and ‘Green Glow’ even can grow with the untreated water of pH 7.5.It is good for extension and breeding,also is a excellent resource for alkali tolerance rootstocks of azalea.