Abstract: Using the calorimeter method and three-dimensional fluorescence spectra technology, characteristics of temperature, heat quantity and dissolved organic matter (DOM) change at different stages of pig manure fermentation process was researched, respectively. The results showed that under different conditions for the C/N in four groups of heat production by fermentation experiments, the time during pure pig manure fermentation with the temperature higher than room temperature lasted for 60days. However, the loss of cumulative heat appeared to be up to 8.862kJ/g, which was the most ideal ratio for this warming technology. With the heat production of pig manure fermentation, protein-like compound (P_1,n+P_2,n,0.625-0.546) gradually decreased in the samples, while fulvic acid-like substance (P_3,n,0.140-0.173) and humic acid-like substance (P_5,n,0.051-0.097) reversely increased. During this process, humification degree was gradually strengthened, but compared with the other groups, the humic acids increased the least and the humification degree was lowest. Additionally, the correlation between fluorescence intensity in different regions and the value of heat production were dissimilar of different ratios of C/N of material, but the released heat of different C/N material was totally derived from the matters decomposed from simple organic compounds by microorganisms.