Abstract: In order to realize resource recycling of kitchen waste, the enhancement of fermentative production of lactic acid（LA）by Rhizopus oryzae AS 3.819 was investigated. Batch experiments were carried out to analyze the effect of pH on the yield of total lactic acid and the distribution of L- and D-lactic acid among total lactic acid during the non-sterilized fermentation of kitchen wastes by rhizopus oryzae AS 3.819. The results showed that when rhizopus oryzae was cultured in medium temperature（34℃）, the optimal growth condition was pH 7, the optimal fermentation condition was pH8. The concentration of reduced sugar（calculated as glucose）was low, and its concentration was higher at neutral and alkali conditions（pH6-8）than at acidic conditions（non-controlled pH and pH5）. The L-lactic acid was the predominant isomer form at pH 8. The maximum total lactic acid production rate was 1g/（L?h）, the ratio of L-lactic acid kept at above 0.75 during the whole experimental fermentation time and reached the maximum value（0.99）at 60 h and the maximum L-lactic acid was 59.8 g/L. To obtain high #br#L-lactic acid yield and optical purity simultaneously, it was suggested that PH should be controlled at 8.