Abstract:According to Vector-subspace （VS）angle criterion，a new method of quick caffeine-analyzing in drinks is created.Using chromatography-mass spectrum analysis to collect UV multi-wavelength spectral databases of common functional drink and Cola，the background databases of functional drink and Cola without tested Caffeine were established，then Caffeine in Red Bulk and Cola was determinate based on Vector-subspace Angle Criterion.The results presented that analysis results were similar to that of High performance liquid chromatography（HPLC），the relative errors were less than 4.0%，the recoveries of standard caffeine which was added in Red bulk drink and Cola samples were in the range of 96.7%-106.0%and the relative stand deviation was less than 2.0%.After the background databases were established，the analysis could be achieved by only collecting the drinks'UV wavelength spectral.The method is rapid and accurate，which could provide the feasible solution to drinks'scene analysis.