The highly ordered two dimensional micro-/nano-sized silver cavity was fabricated by galvanostatic multistep method using ordered arrays of close-packed 700 nm diameter polystyrene spheres as templates. The morphology and the surface plasmon resonance of this silver cavity array were characterized by scanning electron microscope and reflectance UV-Vis spectra, and surface-enhanced Raman scattering (SERS) spectra of p-aminothiophenol (PATP) and Rhodamine 6G (R6G) on as-prepared substrate were also studied. The results show that: the depth of cavities can be easily regulated through varying the parameters of the electrochemical deposition. As SERS substrates for the detection of PATP molecules, the two dimensional Ag cavity arrays exhibit excellent performance and the enhancement factors can be as high as the 107 order. In addition to the high-intensity enhancement, it is also found that the SERS spectra are highly reproducible on this Ag cavity arrays. The relative standard deviation of the peak intensity of PATP molecules at 1 077 cm-1 was calculated to be 8.4%. The as-prepated substrate can be used for the quantitative detection of R6G, and the detection limit reaches as low as 0.1 ng·mL-1.