The magnetic susceptibilities of liquid TI-Te, TI-Se and TI-S systems have been measured at various compositions as a function of temperature. The difference of susceptibility between solid and liquid states at the melting point is quite small at the composition corresponding to TI2X (X= Te, Se and S). The diamagnetic susceptibility of these alloys in X rich region increases on melting, while that of TI rich solutions decreases. The curve of isothermal susceptibility against concentration showed a diamagnetic maximum near the stoichiometric composition. These experimental results are discussed in the light of the bond orbital model for magnetic susceptibility.