The large volumetric contraction effect presented by MnM'X (M' Co, Ni; X= Ge, Si) during the martensitic (MA) transformation displays their potential applications in negative thermal expansion (NTE) field. In this work, we report the giant antiferromagnetic (AFM) NTE in (MnNiGe)(1-x) (MnCoSn)(x) (0.02 <= x <= 0.1) compounds. When x = 0.02, 0.04, 0.06 and 0.1, their average linear NTE coefficients reach -48 ppm/K (220 K - 332 K), -96 ppm/K (174 K-280 K), -92 ppm/K (116 K-220 K) and -35 ppm/K (75 K-130 K), respectively. Moreover, the magnetization shows a descending tendency with increasing x from 0.02 to 0.1, which can be attributed to the more-antiparallel AFM ground state, suggesting their feasible applications in the magnetic environment. (C) 2018 Elsevier B.V. All rights reserved.