The elastic behaviors of star and linear polymer chains confined in parallel interfaces are investigated using pruned-enriched-rosenbluth method (PERM) based on the self-avoiding walk (SAW) model.The simulation results suggest that if the interfaces have the adsorptive effect on the chains

the accretion of the distance between parallel interfaces D needs acting force; while if the interfaces have no attraction

the accretion of D is a spontaneous process. In our simulation

we calculate the changes of the mean-square radii of gyration 〈S2〉 and the shape factor 〈δ*〉 with D

describing the changes of dimension and shape of the star and linear chains.Additionally

in order to understand the structure and the mechanical behavior in more detail

we also study confined chains of different structure such as train

loop

bridge and tail chains.