Anaerobic digestion is an efficient way to dispose and recycle agricultural organic wastes. The performance of anaerobic digestion of pig manure and straw mixture with different mixing ratios was investigated in the paper. Experiments were conducted in self-manufactured anaerobic digestion reactor at 37 ℃ with pig manure/straw ratios of 1∶0

2∶1

1∶1

1∶2

1∶3

0∶1 and total solid concentration 8% in the reactor. The p H

gas production and cumulative gas production were examined during anaerobic digestion. The results showed that when the ratio of pig manure and energy grass quality was 1∶2

the effect of mixed anaerobic digestion was best

which the cumulative methane yield was 1 735 m L.