The reaction between NaHSO3 and H2O2 produced ultra-weak chemiluminescence(CL).Riboflavin could greatly enhance the CL from NaHSO3-H2O2 system.The CL intensity was linearly increased with concentration of riboflavin in the range of 0.02-2.0 μg/mL.Based on the phenomenon,a high sensitive chemiluminescent method was developed for the determination of riboflavin in tablet samples.The detection limit was 0.007 μg/mL and the relative standard deviation was not more than 1.6%.Furthermore,fluorescent and chemiluminescent spectrum was utilized to illustrate the chemiluminescent mechanism,which would extend the application of NaHSO3-H2O2 system.