Abstract: Molecular electronegativity-distance vector (M_t) was used to describe the molecular structures of 165 nonionic organic compounds in this paper. A quantitative linear relationship between 32 M_t descriptors and bioconcentration factor (lg B_CF) of 122 NOC was set up using the method of multiple linear regression (MLR). The satisfactory model of 4 parameters (such as M₁₅, M₁₇, M₃₆, M₉₁) was built by stepwise multiple regression and the Jackknifed method (the leave-one-out, LOO), of which the calibrated correlation coefficient (R) was 0.960 and the validated correlation coefficient (q²) was 0.915. The 4-variable model has shed light on some main structural factors influencing the B_CF on NOC, which shows the good estimation ability and robustness. A prediction power for the external sample of 11 NOC was validated by the model built from the training set with 111 NOC.