A series of Gd1- xNbx(x=0, 1, 2, 3, 5) alloys were prepared by arc melting in purified argon atmosphere. The ingots were heat-treated at 1273K for 96h followed by water quenching to homogenize the microstructure. All Gd1-xNbx alloys with various Nb doping keep the hexagonal crystal structure of pure Gd. The Curie temperatures Tc of the Nb-doped alloys are lower than that of Gd by ~2 K and the magnetic transition occurring in the vicinity of Tc is a second order transformation. The maximum entropy changes of Gd1-xNbx alloys under 5 T magnetic field are about 85% of that of pure Gd. The microhardness of Gd1- xNbx alloys is greatly improved by doping a small amount of Nb (≤5 at%). Comparing with pure Gd, the microhardness increases by about 53% for Gd1-xNbx alloys with x=5. The present results indicate that the Gd1- xNbx alloys with small amounts of Nb doping have large values of magnetic entropy change and good processing properties, they are possessed of great potential in room-temperature magnetic refrigeration applications