The isothermal section of the phase diagram of ternary Ti-Mn-Sn system has been investigated at 770 K. The existence of new TiMnSn 4 ternary compound was established and its crystal structure was determined. TiMnSn 4 stannide crystallizes in the Mg 2 Ni structure type (space group P6 2 22, a=0.55537(1) nm, c=1.40326(2) nm). For the given compound the temperature dependences of electrical resistivity, differential thermopower and magnetic susceptibility were investigated. On the basis of binary Mn 3 Sn, Ti 6 Sn 5 and Ti 3 Sn compounds the solid solutions were formed.