PENTENS T-007 cement modifier is belonged to the copolymer of styrene., being modified from MMA, and butadiene. If add which into cement and mortar, that can permeate into the gap between cement and aggregate to fulfill its function of filling pore space, that will enable the cement and mortar more and more fine in texture and further to enhance the water proof and durability for cement and mortar. Plastering on the surface of engineering cement, it not only can adhere firmly with concrete, but also can protect concrete from the osmosis of water contents and to avoid the corrosion of reinforcement and aging of cement. Application on the joint adhered by new and old cements, that can cure the light powder dust on the construction surface and further enable the firm adhesion between the water proof layer and construction surface so as to enhance the adhesive strength for the water proof material.