Biochar have been applied as soil ameliorant to improve soil quality and microbialactivity.However，the effectof biochar on soil characteristics and microbial activities in acidified tea plantation in red soil is still not wellunderstood.Therefore，a field experiment was carried out to study the effects of wheat straw biocharapplication(0，10，20，40 t/hm²)on soilchemical characters，microbial properties and enzyme activities of tea plantation in Anxi，Fujian.The results showed asfollows:Compared with thecontrol，application of 40 t/hm² biochar significantly decreased the soil bulk density by 0.23 g/cm3and soil alkaline hygdrolyzable nitrogen content by29.2%，while significantly increased the soil organic matter，available phosphorus，and available potassium content by62.1%，153.9% and173.6%，respectively.Likewise，soil pHincreased by 0.88units.As the amount of biochar amendment increasing，the numbers ofbacteria，actinomycetes，fungi， potassium dissolving bacteria and phosphate-solubilizing bacteria significantly increased by 28.5%～104.4%，27.2%～123.4%，17.0%～35.9%，109.2%～ 208.2% and 150.0%～ 337.3% in the teaplantation，respectively.Meanwhile，application of biochar significantly increased the activities of β-Glucosidases，urease and soil alkaline phosphatase by 45.5%～114.7%， 8.6%～ 21.5% and 26.7%～186.6%，respectively，but decreased the activity of acid phosphatase by 4.0%～15.6%. Therefore，biochar is an effective amendment to improve soil properties and soil nutrients condition in acid tea plantation soil in redsoil.