RF plasma enhanced chemical deposition was used to get biocompatible coating on polymeric substrates with various processing conditions, such as input power, monomer/oxygen feed ratio, modulated frequency and duty cycle. Allylamine was used as feed monomer and oxygen was used as mixing gas. Input power was varied from 50 to 300 Watt. Deposition rate was 16 nm/min. Chemical bonding information of deposited film by FTIR-ATR showed peak broadening compared to the allylamine monomer and C=N stretching peak near 2200 cm@super -1@ appeared for polymerized coating. Contact angle was changed from 88° for untreated polystyrene to 30° for treated polystyrene without oxygen input. Contact angle of plasma polymerized allylamine coating obtained with oxygen input was 8°. Untreated polystyrene film had rough surfaces and the average roughness was 10.91 nm, however, the plasma coating deposited polystyrene with introduction of oxygen, the roughness decreased to 3.91 nm and it decreased to 1.98 nm without oxygen input. ESCA showed N/C ratio of 13.4, 4.36 for samples prepared with oxygen input and without oxygen, respectively. Fibroblast cell was used and MTT assay was done. Cell viability 4 days after seeding was decreased as amount of oxygen increased.