The inhibition effect of excellent environmental-friendly corrosion inhibitors-Vitamins B of hot dipping Zn coated steel in diluted HCl was investigated using quantum chemistry analysis and weight loss test. Calculation result shows Vitamins B have a number of active centers. The value of Mulliken charge, distribution of HOMO and LUMO implies its good ability of electron exchange with metal surface. The test results indicate IE% increased with the inhibitor concentration, and the highest IE reached 97%.