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The use of anaerobic fermentation technology of agriculture wastes for the production of volatile fatty acids (VFAs) is a promising approach. The aim of this investigation was to evaluate the different pretreatments of rice straw like hydrothermal, acid and alkali on the AD process parameters and the VFAs production at mesophilic (35℃), thermophilic (55℃) and hyper-thermophilic (70℃). The results showed that the alkaline pretreatment was more favorable for VFAs production than acid and hydrothermal treatments. The lignin degradation rate with Ca(OH)2 at 35℃ was 63.27%, which was much higher than that of hydrothermal treatment group (12.45%) and that of HCl treatment group (12.40%). The pH value was in the range of 6±0.5 at alkali pretreatment. The efficiency of converting the degraded straw into VFAs at mesophilic was high, resulting in the highest VFAs yield. The VFAs yield with per degradation volatile solid in the pretreatment group was 0.79 ~ 1.20g/g and 0.24 ~ 0.51g/g at 35℃ and 70℃, respectively. The preferred alkali treatment group gave a yield of VFAs production of 0.25g/g at 35℃ and 0.09g/g at 70℃, respectively. The results can provide some theoretical basis to enhance the VFAs production from rice straw under different conditions.