In order to explore the effect of ethylene treatment on the quality of mango fruits, two concentrations of AVG(aminoethoxyvinylglycine), which will inhibit ethylene formation after application, were sprayed either on the fruit surface or on the leaves of fruit-setting branches, once a week in the late fruit development stage on the two mango varieties ”Chiin Kwang” and ”Irwin” mango. Results varied in varieties. On Chiin Kwang, the later the treatment, the larger the hue angle (θ value), meant the green color more significantly, and no difference was observed in the other characters. On Irwin, however, no differences were observed among treatment in fruit hardness, °Brix, and acidity or postpone the harvest stage. Therefore, more research is need before the use of AVG on mango to improve its fruit quality.