We study surface properties of poly(n-hexyl isacyanate) (PHIC) by surface pressure measurement and fluorescence microscopy under compression and expansion cycles at different temperatures. PHIC forms a stable film at the air-water interface, and it leads to a multilayer film at lower surface area. Film stability of PHIC during the compression and expansion cycles depends on the final surface area. When the final surface area is well in the region of multi-layer formation, namely the plateau region, irreversible hysteresis is observed, On the other hand, a PHIC film with a larger final surface area than the plateau region shows reversible behavior. At higher temperature PHIC film is more easily desorbed from the air-water interface due to the weaker hydrogen bonding between the isocyanate group and water.