Abstract: To determinate the concentration of TiO₂ in functional fiber for labeling purpose,the sample was nitrified with burning and dissolved in mix acid as pretreatment and then its concentration of TiO₂ was determined by spectrophotometric method with ascorbic acid as shelter reagent of Fe³⁺ and Cu²⁺ and diantipyryl methane(DAPM) as developer at wavelength λ=(390 nm.) A good linear relationship was exhibited with the mass concentration of Ti at the range of(0.005～)(0.65 mg/L,) linear equation y=(1.407 1x)-(0.009 3)(R~2=0.999),the detection limit was(0.005 mg/L,) the average recovery ratio was above 98%,and relative standard deviation(RSD) was 0.59%.The method is simple and fast,high accuracy and practicability.