In Cambodia, rice liquors or Sra Sor is locally produced in large amounts every year. This traditional beverage is made from the combination of rice starch with different traditional starters consisting of molds and fermenting yeast. Recently, the quality and the ethanol yield of rice wine produced by traditional starter were notably low. Thus, the utmost concern is to improve the quality of the product in terms of physicochemical and sensory properties, yield, and to establish the quality control system throughout the process. The objective of this study was to improve the processing technique of rice liquor production by using Rhizopus oryzae with Saccharomyces cerevisiae and alpha- amylase. The physicochemical parameters including pH, acidity, total reducing sugar, glucose, maltose, lactic acid, acetic acid, ethanol, and methanol were investigated during fermentation and at the end of fermentation. The results showed that during fermentation, pH of all conditions decreased gradually over the time and reached the finally pH values around 3.09 ± 0.01 to 4.33 ± 0.04, while the concentration of acidity increased remarkably until the end of fermentation around 3.12 ± 0.064 g/l to 8.42 ± 0.45 g/l. This result was in accordance to ethanol production found highest of 9.66 ± 0.08 % (v/v) at the same condition. In conclusion, using alpha-amylase in the rice wine production process provided notable results with highest yield of ethanol and lower acidity by comparison to the control without enzyme. Thus, the mixture of R. oryzae, S. cerevisiae with the addition of alpha-amylase is a good process design for further study as well as industrial scale.