Abstract: The visible spectra of chromium in ferro-alloy were analyzed by digital automatic analysis system. The characters of Cr 520.60 nm and Cr 534.58 nm line groups in ferro-alloy were studied and the colored digital spectra for these line groups were produced. The digital analysis method was developed for spectroscopic analysis of chromium in ferro-allny and can he applied to the qualitative and the quantitative analysis of chromium in ferro-alloy and also can be used in the identification of alloy marks.