The dispersion of carbon nanotubes (CNT) will directly influence the performance of CNT-cement composite. In this article, different surface-active agents were tried in dispersing the CNT in the water. Through standing and centrifugal treatment, the dispersion of CNT in the water was evaluated. The CNT was also mixed with cement. By testing the resistivity of CNT-cement composite, the dispersion of CNT was studied and evaluated. The results showed that standing, centrifugal treatment and measuring the resistivity were all effective ways in testing and evaluating the dispersion of CNT.