A new kind water-proofing additive can fundamentally prevent water absorption through the capillary pore and keep chlorine ion out of the concrete structure,so as to prevent reinforcement corrosion.This paper studies the performance of the new-kind water-proofing additive,including the influence on both mortar and concrete;Takes the lead to use the British Standard to evaluate the water absorption rate of concrete;Furthermore,it compares it with the same-kind similar foreign products.The new-kind water-proofing additive can improve 7 d and 28 d compressive strength and the anti-permeability of both mortar and concrete in case of no changing the working performance.