2-Vinyl-4,6-diamino-s-triazine (VDAT) was polymerized in aprotic solvents with the basic initiators potassium tert-butoxide (tert-BuOK), sodium methoxide, and n-butyllithium. It was confirmed by IR and NMR that the polymerization progressed by hydrogen transfer. The catalytic activity decreased in the order cited. In the case of tert-BuOK, the mechanism of initiation was investigated by NMR of the polymer obtained at the initial stage and gas chromatographic determination of tert-butanol in the reaction mixture, and the mechanism of propagation was investigated by viscosity measurements, copolymerizations with divinyl compounds, and fractionation of the copolymers. The results showed that the initiation started with hydrogen abstraction by the initiator anion, and that propagation proceeded by inter-molecular hydrogen transfer.