To investigate the effects of biochar on water stable aggregate structure and distribution of carbon and nitrogenin subtropical red soil，in this study，biochar which prepared from spent mushroom substrate was applied in a short -termpot experiment to study the soil aggregate structure and distribution of carbon and nitrogen after biocharapplication.Theresults showed that:(1)The particle sizes of soil water stable aggregates were mainly less than 0.25mm，and its contentin biochar combined with chemical fertilizer treatment was the highest，which was65.88%，and the biochar increased thewater stable aggregate content in >0.25 mm soil particle size by40.52%，but the application of chemical fertilizers and pigmanure reducedit，the decline rate was 43.33% and 25.33% respectively.(2)Biochar combined with chemical fertilizerand pig manure significantly improved soil water stability mean weight diameter and geometric meandiameter.(3)Biocharsignificantly increased soil and organic carbon，total nitrogen content and the ratio of C/N，with an average increase of 154.76%，74.05% and30.16%，respectively.Insummary，biochar application is beneficial to increase the stability and content of water-stable large aggregates in subtropical red soils，and the effect on soil carbon and nitrogen content is more significant.