Abstract: Relationship between bioconcentration factor and fragment constants was investigated. Aprediction model was developed on the basis of the observed BCF values of 80 non-polar organic compounds. The precision of the model was evaluated using adjusted coefficient of determination and studentized residuals. Jackknife tests was applied to examine the robustness of the prediction model. The coefficient of determination and the mean residual of the model was 0.995 and 0.1836, respectively.