In this paper, structural and magnetic studies are carried out on the alloys of the iron-rich Nd-Fe-B ternary system. The results show that for the iron-rich (Fe>40 at%) alloys ternary compound Nd2Fe2Si2 is formed (Si>20%) as well as pseudobinary compound Nd2(Fe, Si)17, in which Si atoms are substituted for the iron atoms on 9d-sites instead of forming new ternary compound as that of Nd2Fe14B. Upon substitution of Si for Fe, both cell volume and magnetization of the Nd2(Fe,Si)17 alloys decrease, but Curie temperature Tc increases due to an enhancement of the ferromagnetic interaction in the Fe sublattice. The room temperature anisotropy fields decrease with increasing Si eon-tent as a result of reduction of the plane anisotropy in the Fe sublattice.