The complex [Cu( μ3-I)INH]n has been synthesized in DMF solution with INH, CuI, where INH=isoniazid. The crystal structure of the complex has been determined by X-ray diffraction single crystal structure analysis. The crystal belong to monoclinic system, space group P21/c. The cell parameters are: a=1.009 48(10) nm, b=0.467 51(5) nm, c=1.992 62(19) nm, β=101.413 0(10)°, and V= 0.921 81(16) nm3, Z=4, μ(Mo Kα)=5.674 mm-1, F(000)=616.0, R1=0.031 6, wR2=0.082 5 [I>2σ(I)]. The copper(Ⅰ) atom locates in a distorted coordination tetrahedron. The copper(Ⅰ) atoms bridged by μ3-I to form a band stair-like chain, and INH occupying the remaining coordination site of the approximately tetrahedral. The stair-like chains extend along b axis. The results of TG analysis show the title complex was stable under 200℃.