Abstract: In a Tris-HCl buffer medium of pH 3.96,the hydrolysate of reserpine (an alkaloidal drug) was reacted with the protonized victoria blue B to form a hydrophobic ion association complex giving strong signal of resonance Rayleigh scattering (RRS) at the wavelength of 421 nm.Linear relationship between values of RRS intensity (ΔIRRS=Is,RRS-I0,RRS) and mass concentration of reserpine was kept in the range of 0.40 to 6.40 mg·L-1,with value of detection limit (3sb/k) of 18.27 μg·L-1.The proposed method was used to analyze 2 samples of reserpine injections,and tests for recovery and precision were made by standard addition method using these samples as matrixes.Values of average recovery and RSD′s (n=6) found were 101.0% and 2.1% respectively.