In polymer modified cementitious materials, it is hard to set up a chemical connection between the added polymer and the cement moiety. In this study FS (functional silane) was adopted to form this connection as a bridge component which has the functional group forming bonds with polymer. To testify the connection between FS and cement moiety, Q /Q ratio (Q : intensity ratio) investigation was carried out by the means of quantitative solid state 29Si MAS NMR. The results show that the Q /Q ratio has increased with the addition of FS which indicates that the silicon chain length has increased, and the quantity of silicon atoms at site of Q , chain site, has enhanced, showing that the silicon atom of FS has connected to the silicon chain of cement moiety by the bond "-Si-O-Si-" formation. © 2014 Wuhan University of Technology and Springer-Verlag Berlin Heidelberg.