Improper treatment of pig manure in the farm could cause serious environment pollution. The degradation of pig manure can provide scientific basis for the use of farm manure. The effects of inoculated compound microbial agents(including bacillus, yeast, lactic acid bacteria and photosynthetic bacteria) on the fermentation of organic matter, total phosphorus (TP), total nitrogen (TN), nitrate nitrogen(NO₃^--N) and ammonium nitrogen (NH₄⁺-N) at the conservation and fattening stage were investigated by constant temperature test. The results showed that compound bacterium agents could increase the degradation rate of the organic matter and the inversion of TN and NH₄⁺-N compared to the blank experiments. At the conservation stage, the degradation rates of TN, NH₄⁺-N of pig manure by T2, T3 treatment were decreased by 20.3 and 66.7%, respectively, whereas the degradation rates of TN, NH₄⁺-N by T1 treatment were decreased by 17.8% and 55.7% , respectively, compared to the blank experiments ( 17.3% for TN and 50.7% for NH₄⁺-N). At the fattening stage, the degradation rate of NH₄⁺-N (66.7%) was higher than that of the blank experiments (50.9%). The inversion of NO₃^--N at last phase was increased with decreasing of NH₄⁺-N. No significant difference ( P > 0.05) in the degradation of pig manure was observed when the amount of compound bacterium agent was more than 5 g. The same trends of organic matter, TP, TN, NO₃^--N, NH₄⁺-N were observed at the conservation and fattening stage. The calculation results showed that the nitrogen cycle of pig manure in plant and livestock system tend to balance in fertilizer.