In this paper, a study is presented on the microstructure of a cement-based PZT (Lead Zirconate Titanate) piezoelectric ceramic composite. A mechanism is proposed for chemical bonding between piezoelectric ceramic particles and cement material in the composite. The microstructure of the composite, as well as chemical bonding at the ceramic–cement interface is investigated using XRD, IR and XPS. Experimental results indicate that Ti–O in the ceramic particles links to Si–O in the cement paste via bridging oxygen, forming a Ti–O⋯Si–O bonding. And the change of chemical environment takes place for all of Ti, Si, Ca and Zr for cement-based piezoelectric ceramic composites. One prominent result pertaining to chemical reactions at the interface between ceramic particles and cement paste shows that Ti diffuses into the cement paste via Ti–O⋯Si–O bonding.