The Hamiltonians of two and three particles moving on d-dimensional lattice and interacting via pairwise short-range potentials are studied.
The following new results are established:
(i).The existence of eigenvalues for the two-particle Shr\"odinger operators depending on the quasi-momentum.
(ii). Infiniteness the number of eigenvalues(Efimov's effect) of the three-particle Shr\"odinger operators
for the zero value of quasi-momentum and its finiteness for the non-zero values of the quasi-momentum.
(iii).The corresponding asymptotics for the number of eigenvalues.