The addition of manganese into Nd9Fe85-xMnB6 (X = 0,0.5,1) was found to enhance the magnetic properties of alpha - Fe/Nd2Fe14B magnets. After optimal annealed, the coercivity and remanence ratio increased from 0.34MA/m to 0.4MA/m and from 0.70 to 0.72, respectively, for the increase of x from 0 to 1. The XRD patterns indicated the addition of manganese could promote crystallization of as-spun samples. Moreover, the XRD spectra showed almost same grain sizes obtained for the optimal annealed samples. Thermomagnetic analysis (TMA) measurement indicated that the doping of Mn reduces the T-C of the Nd2Fe14B phase and raises that of alpha - Fe phase in the system. It is believed the exchange coupling between the Nd2Fe14B phase and alpha - Fe phase was partly changed by Mn addition, which is the reason for the enhanced magnetic properties and the change of T-C.