Abstract: The spetrophotometry analytical method of mercurry was developed based on the colour reaction of Hg(Ⅱ)-SCN——RhB system in the presence of β-cyclodextrin and polyvinyl alcohol in the medium of hydroloric acid.The maximum absorbance is at 580 nm with apparent molar absorption of 4.97 × 105 L·mol-1·cm-1.The beer’s law is obeyed in the range of 0.03~0.4 mg/L.The regression equation of calibration is A=0.092ρ + 0.007 1 with a correlation coefficient 0.988 4.The proposed method was used to determine t...