Based on topological chemical theory

a newly developed topological indices Tp1

Tp2 and the structural information indicating variable I were used to describe the local chemical microenvironment of 35 nitrobenzene derivatives.The quantitative structural-activity relationship（QSAR） model for estimating the biological toxicity of 35 nitrobenzene derivatives was developed based on the newly introduced topological indices Tp1

Tp2 and the structural information indicating variable I by partial least regression（PLS）.The experiment result showed that the QSAR topological model correlation coefficient and standard error were 0.981 8 and 0.151 6

respectively.And the average relative error was only 1.09% between experimental values and calculated values for the biological toxicity of 35 nitrobenzene derivatives.To validate the estimation stability for internal samples and the predictive capability for external samples of resulting models

leave-one-out（LOO） was performed.And the results show that the models all have good stability and predictability.