The Mossbauer spectra of amorphous alloys Fe80B20-xMx (M = P, C) at room temperature and 4.2 K have been measured. It is found that the mean values of the hyperfine field and the isomer shift vary linearly when M (P, C) substitutes for B. Two structure models of amorphous alloys, microcrystal model and Bernal-Polk model, have been compared using these results and that of their crystalline counterparts. The study suggests that there do not exist a microcrystalline short range order and corresponding transition in amorphous alloys TM-M as in the crystalline counterparts. For describing the microstructure of amorphous alloys TM-M the Bernal-Polk model is preferable to the microcrystal model.