The mitigation effects of exogenous Ca²⁺ on waterlogginginduced damages to agronomic and physiological indexes of pepper cultivar Bolahongniu were investigated by spraying Ca²⁺ on leaves surface at different days. The results showed that: (1) the biomass, seedling index, chorophyll contents, root activity, proline, soluble sugar, SOD and CAT activities of pepper seedlings showed a trend of increasing firstly, then decreasing with spraying days increase. MDA content showed a trend of decreasing firstly, then increasing with spraying days increase. (2) Spraying calcium one day treatment(T_1d) showed no significant mitigation effect under waterlogging damage for pepper. Spraying calcium 3 days treatment(T_3d) and spraying calcium 6 day treatment(T_6d) showed the increased mitigation effect gradually. Spraying calcium 9 days treatment(T_9d) achieved the best results, while the mitigation effect gradually weakened with spraying calcium 12 days treatment(T_12d) and spraying calcium 20 days treatment(T_20d), but still significantly better than that of T_1d treatment. Overall, the results suggested that Ca²⁺ might mitigates waterlogginginduced damages to pepper and achieves better alleviation effects by spraying 9 days.