Abstract: In order to promote the exploitation and utilization of sweet sorghum silage, three kinds of silages (high sugar sweet sorghum silage, HSS; low sugar sweet silage, LSS; maize silage, MZS) were used to analyze the changes in dry matter (DM), water soluble carbohydrates (WSC), pH, temperature and microbial populations during aerobic exposure over 0, 5, 10, 15, 20 and 25 days. The results showed that HSS had a lower pH and higher LAB (lactic acid bacteria) population and higher temperature compared with LSS and MZS (P<0.05) in the early stage of aerobic exposure (0-5 d). The numbers of yeast, mould and aerobic bacteria in HSS were higher than that in LSS and MZS (P<0.05), while temperature and pH were lower in LSS than those in HSS and MZS (P<0.05) in the latter stages of aerobic exposure (15-25 d). HSS had the highest WSC and LSS had the lowest dry matter content (P<0.05) over all exposure periods. Overall, LSS had the greatest aerobic stability with less yeast, mould and aerobic bacteria which were highest in HSS which had the lowest aerobic stability; bacteria numbers and aerobic stability were intermediate in in MZS. The results of this study suggest that it is necessary to use additives when making HSS to assure quality because it is more prone to secondary fermentation under aerobic exposure.