AbstractThe thermodynamical properties of the star‐branched polymers on the tetrahedral lattice are studied taking into account nearest‐neighbor interactions. The excess free energy and energy and heat capacities are computed for wide ranges of chain lengths, reduced potential ϵ/kT, and number of branches. A significant influence of the degree of branching on long‐range interactions in the polymer random coil is observed. The possibilities of phase transitions in both linear and branched systems are discussed on the basis of the Monte Carl