Surface Enhanced Raman Scattering (SERS) characteristics of Thiourea $(SC(NH_2)_2)$ adsorbed at Ag electrode was studied in 0.1 M $H_2SO_4$ and 0.1 M HCl aqueous electrolytic solution. The result show that Thiourea is adsorbed at the Ag electrode via sulphur atom and forms a surface complex in coordination with anions and adatoms. The anionic effect and voltage dependence of various SERS peaks were explained in terms of charge transfer-surface complexes. At lower PH values the SERS spectral intensity was observed to increase. Some Raman band, not observed previously in normal Raman Spectrum, was observed for the first time in SERS spectrum. Though Thiourea remains neutral in aqueous solution it seems to affect the voltammogram of the SERS electrolytic solution.