In this paper, we propose a new kind of precoding method, modulated coded vector-TH precoding, to mitigate the channel intersymbol interference. The optimal design of the modulated code in vector TH precoding is presented. The coding gain of modulated coded vector TH precoding over conventional scalar TH precoding scheme is investigated in theory. Some simulation results are reported, which show that the proposed modulated coded vector TH scheme can provide a considerable coding gain compared with the conventional precoding techniques.