A new yellow-orange substance was isolated from the cells of Propionibacterium shermanii grown in a medium containing cobinamide. The compound exhibited the coenzyme activity in the intramolecular oxidation-reduction system of Abeles・Lee. Its Km value was 6×10^<-6>M, 20 times as much as that of DBCC. It moved to cathode 1.5 times faster than cobinamide cyanide, hydroxo-cobalamin and DBCC at acidic pH in paperionophoresis, and gave the same spot as that of cobinamide cyanide after cyanide treatment. The shape of its absorption spectra in a neutral solution was analogous to that of DBCC except a difference in the wave length of the absorbancy maximum at 460mμ. The spectra was replaced by a spectra with double peaks at 350 and 500〜550mμ by exposure to light and changed to the spectra of cobinamide dicyanide by cyanide treatment. It exerted a little activity on E. coli mutant which was known to show a weak response to cobinamide and the derivatives. From these results, it would be concluded that the yellow orange substance was a coenzyme with cobinamide structure.