Abstract: In order to reduce nitrogen loss in process of corn straw aerobic composting, C/N value was adjusted by ammonium sulfate or urea, and ammonia emission and nitrogen retention in process of composting covered by nano membrane were tested．Results showed that fermentation temperature of ammonium sulfate treatment（T₂）from 7 d to 60 d was higher than that of urea treatment（T₁）．The maximum concentration of NH₃ in membrane of T₁ was 0.045%, while NH₃ was not detected in membrane of T₂．Composting products' pH values at 0 cm and 50 cm of T₁ increased to 8.34 and 7.86, which of T₂ decreased to 6.04 and 6.28 respectively．Dry matter loss rate, total nutrient content, seed germination index and C_HA/C_FA of composting products in T₂ were higher than those in T₁．Compared with T₁, nitrogen loss rate of T₂ was reduced by 24.59%．Except water content, physicochemical properties of composting products of T₁ and T₂ met requirements of NY/T 525—2021 "Organic Fertilizer"．