Objective To explore the relationship between skin photo reactions and structural pa-rameters. Methods Benzophenone-1, Benzophenone-2 and Benzophenone-3 were assessed by phototoxici-ty test and photoallergic test on guinea pig. And the phototoxicity index and photoallergic index were cal-culated after clinical assessment. Structural parameters of the three sunscreens like total energy, binding energy, electronic energy, heat of formation, dipole and sum of the net charges were also calculated by the soft of HyperChem7.0, respectively. Results The phototoxicity index rised with total energy, elec-tronic energy and sum of net charges increasing. And the photoallergy index rised only with binding ener-gy increasing. So there was some correlation between phototoxicity index and total energy, electronic en-ergy and sum of net charges (P<0.01). Significant relationship was only between the photoallergy index and binding energy (P<0.01). Conclusions The phototoxicity is correlated with total energy and e-lectronic energy, while photoallergy is related to binding energy. It is possible to establish a model evalua-ting the safety and structural parameters of benzophenone ramifications.