Growth of Cu thin film on Au substrate and stress evolution were modeled using molecular dynamics simulation. The Au substrate consists of an unmoved layer and a regular strips as a grains. The interactions in the system are described by embedded atom method. We considered two cases of the substrate: substrate with different lateral correlations, and substrate with different size of grains. For larger distances between strips/grains larger compressive contribution are observed. Thicker deposited film is also needed to stress change in the tensile direction. Moreover, the grain size effect plays an important role in stress generation. For the film thickness of about 1 ML we observed occurring of extreme on the stress curves. Collapse of the direction of stress changes suggests the appearance of a new mechanism for generating tensile stress in the system. Appearance of tensile stresses during the deposition is associated with the coalescence of the copper grains with gold grains during the layer growth.