  In the present paper we compute the Jacobian group of $\Delta$-graph
$\Delta(n; k, l, m).$ The notion of $\Delta$-graph continues the list of
families of $I$-, $Y$- and $H$-graphs well-known in the graph theory. In
particular, graph $\Delta(n; 1, 1, 1)$ is isomorphic to discrete torus
$C_3\times C_n.$ It this case, the structure of the Jacobian group will be find
explicitly.
