Abstract: For food safety problems caused by aflatoxin B₁( AFTB₁) pollution the paddy,the change lows of content of AFTB₁ with the time and amount of Aspergillus flavus and the relationship between the initial content of AFTB₁ and degradation rate by ozone were investigated in storage of paddy.The results showed the content of AFTB₁( X)was significantly parabolic relationship with storage time( T) and positive linear relationship with counts of Aspergillus flavus( M) in 16.0% moisture content of paddy at 30 ℃,and the regression equations were X = 3.958T²-30.523 T + 45.049( R²= 0.945,p < 0.01) and X = 3.031E- 005 M + 12.311( R²= 0.955,p < 0.01),respectively.The detoxification rates of AFTB₁ rose in the first stage,and then decreased with the increase of the initial content of AFTB₁ in paddy.The maximum degradation rate of AFTB₁ was 88.1%,and the paddy with AFTB₁of68.42 μg / kg was reduced to the national limited standard( 10 μg / kg) at given conditions.