By the means of first-principles computations,we investigated the geometries,stabilities,electronic and magnetic properties of fully and partially hydrogenated germanium nanoribbons(GeNRs).Independent of chirality and ribbon width,all of the fully hydrogenated GeNRs(fH-GeNRs)can exhibit the non-magnetic semiconducting characteristic with a band-gap of 1.156~1.846 eV,where their band-gap slightly decreases with the increase of ribbon width.By hydrogenating GeNRs from both the edges to center step by step,we also obtained partially hydrogenated zigzag GeNRs(pH-zGeNRs)and armchair ones(pH-aGeNRs),which can be viewed as the combination of hydrogenated and pristine GeNRs.Our computational results reveal that the different electronic and magnetic proerties can be observed between pH-zGeNRs and pH-aGeNRs.Specifically,the pH-zGeNRs can exhibit the antiferromagnetic ground state and a band gap about 0.2 eV(much smaller than those of fH-zGeNRs),where the hydrogenation ratio has almost no effect on the band gap.Contrastively,all of the pH-aGeNRs are nonmagnetic semiconductors with the three-families-behavior(Na=3p,3p+1 and 3p+2),and their band gaps can be almost same as the prinstine aGeNRs,whose ribbon width is equal to the unhydrogenated part of correlative pH-aGeNR.Obviously,the hydrogenation is an effective approach to tune the band structure of GeNRs,which will be advantageous for promoting Ge-based nanomaterials in the application of multifunctional nanodevices.