Based on the long-term site-specific experiment station of Beijing Academy of Agriculture and Forestry SciencesatFangshan，the effects of long -term fertilization on soil organic matter nutrients and microbial characteristics were studied with winter wheat-summer maizerotation.The results showed that after 12 years of long -term fertilization，NPK combinedwith organic waste fertilizer and NPK combined with straw reduced soil pHvalue，NPKWN treatment had the most obviouseffect on reducingpH，which was 0.18 lower than that of the basic soilsample.However，the soil pH value of singlefertilizer treatmentincreased，and there was no significant difference betweentreatments.Compared with CKtreatment，fertilization increased soil ECvalue，and the EC value of soil treated with organic waste fertilizer and straw was higher thanthat of NPK treatment.Long -term application of organic waste fertilizer and straw significantly increased soil fertility，andthe change of soil organic matter and total nitrogen was asfollows:NPK combined with organic waste fertilizer>NPK combinedwith straw>chemicalfertilizer>CK.Compared withCK，the number ofbacteria，fungi and actinomycetes in soilincreased. The amount of bacteria and actinomycetes in soil increased significantly when chemical fertilizer was combined withorganic waste fertilizer or straw.The number of fungi in soil treated with NPKJG was the highest，reaching 4.53×10 4/g，which increased by 67.7% compared with CK.The change of soil microbial biomass nitrogen in different fertilizationtreatments ranged from 24.7 to 44.6mg/kg.The change of soil microbial biomass nitrogen in each treatment was NPKWN>NPKLJ>NPKJG>NPKJF>NPKMG>NPK>NPKHSF>CK，which increased by80.7%，80.4%，77.2%，72.1%，61.2%，35.7% and 23.7% respectively compared with thecontrol.The quantity of soil microbial biomass nitrogen and bacteria waspositively correlated with soil organicmatter，total nitrogen and availablephosphorus，and the quantity of soil actinomyceteswas positively correlated with soil availablepotassium，organic matter and totalnitrogen，which could be used as biological indicators of soil fertility change under long-termfertilization.