We present results of magnetization, AC susceptibility and heat capacity measurements on polycrystalline CeNi1-xCoxGe2 samples (x = 0, 0.025, 0.05, 1) which were prepared by arc melting and on crystal CeNiGe2 grown by optical floating zone method in four mirror furnace. The parent compound CeNiGe2 is an antiferromagnetic Kondo system that orders magnetically at TN = 3.8K and undergoes a spin structure rearrangement at T1 = 3.2K while CeCoGe2 is a nonmagnetic heavy-fermion Kondo compound with j = 5/2 ground state and large Kondo temperature TK > 200K. Our measurements showed that the phase transition from the paramagnetic to the antiferromagnetic state was suppressed to lower temperatures with an increasing concentration of dopant.