Abstract: The development of complex high nutrition foods, such as vitamin B complex, and pharmaceuticals demands simple, rapid and effective methods to determine the multi-component vitamins simultaneously.In this paper, based on the matrix method, an ultra-violet spectroscopic method was developed to determine the four components in VB complex. Using CPA spectroscopic computing method, VB₁, VB₂, VB₆ and niacinamide could be analyzed simultaneously. A BASIC computer program was developed. In this method, the recoveries of the vitamins were 95～105% and the standard deviation was 3.58%. Therefore, a new way was pointed out for the simultaneous analysis of multicomponent vitamins.Also included were the examination of the main factors that affect the precision of quantitation and errors in measurement and computation.