The SERS quality of cobalt and palladium and platinum (CPP) is calculated and analyzed using Antenna Resonance Model. The result from calculation of enhancing factor is 1 and about 4 and 2～4 for CPP respectively. The experimental result is about 5 and 105 and 140 accordingly. Results from the theory and tests are consistent. When the chemical effect is brought in consideration. SERS spectrums of cytosine are obtained from pieces of CPP treated by ORC. Strength of the spectrum is not coincident and the largest is for platinum smallest for cobalt. Moreover, Enhancing abilities of vibrating models of cytosine on three pads are basically homology.