Abstract: A method of Spectrophotometric determination of small amounts of zirconium with chrome azurol S (CAS) in the presence of non-ionic surfactants TritonX-100 was investigated. The color of zirconium complex is blue in a pH range from 5.7 to 6.6 at 605 nm and is stable for at least 120 minutes. Beer's law is obeyed up to concentration of 1.25 μ g/ml of zirconium. The molar extinction coefficient of the complex at 605 nm is 3×10⁴ mol^-1 cm^-1. The complex composition of zirconium to CAS was confirmed to be 2:3 by continuous variation method. A number of ions which interfere with the determination can be masked by the addition of various masking agents.