We report a facile method of generating ultradense poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) surface by using high temperature alone, which in turn provides dramatic :improvement in resisting nonspecific bioadsorption. X-ray photoelectron spectroscopy (XPS) revealed that the surface graft density increased similar to 4 times higher on the surface prepared at 80 degrees C compared to 20 degrees C. The studies from Small-angle X-ray. scattering (SAXS) and the effect of varying ionic strength during/post assemblies at 20 and 80 degrees C indicated that the "cloud point grafting effect" is not the cause for obtaining high density grafting. Stringent long-term bioesistance tests have been,conducted and the temperature-induced PLL-g-PEG surfaces have achieved (1) zero mamalian cell adsorption/migration for up to 36 days and (2) extremely close to zero protein adsorptions have been observed even after 36 days in 10% serum media and 24 h in whole blood within the ultrasensitive detection limit of time-of-flight secondary ion mass spectrometry (ToF-SIMS).