Abstract: Phenol, which is diluted by 0.3 mol/L NH₃·H₂O or 0.005 mol/L NaoH,is determinated by spectrophotometry which follows Lanbert-Beer law in the concentration range 0.1 2.5 mg/L. with recovery of 85% 96% The solid reagent and colorimetric quantity analysis are adopted by standard coloured paper in test field. The method is easy to use and with rapid effect. It can be applied to the determination of phenol on the site of industrial waste water existed.