A one-dimensional cobalt(II) coordination polymer, [Co(btm)(2)(SCN)(2)center dot H2O](n) [btm = bis(1H-1,2,4-triazol-1-yl)methane], was synthesized and magnetically characterized. The isolated slightly distorted octahedral Co-II ion displays field-induced slow relaxation with a big positive axial and a negative rhombic magnetic anisotropy (D = 93.9 cm(-1) and E = -10.5 cm(-1)), and the anisotropy energy barrier is 45.4 K.