Three novel lead iodine dialkyldithiocarbamates, i.e., one two-dimensional (2D) layered [PbI(S 2 CNMe 2 )] n (1), and two one-dimensional (1D) step chain [PbI(S 2 CNC 4 H 8 )] n (2) and [PbI(S 2 CNC 5 H 10 )] n (3) have been successfully synthesized by reactions of NaS 2 CNR 2 (R 2 =Me 2 , (CH 2 ) 4 , and (CH 2 ) 5 ) with lead salts in N,N-dimethylformamide (DMF) solutions, and characterized by elemental analyses, IR, PXRD and single-crystal X-ray diffraction. The structure determinations reveal that Pb 2+ ions in these compounds are all coordinated by three cis μ 3 -I − ions and three cis sulfur atoms coming from the S 2 CNR 2 − anions in octahedral geometry. From the size of the alkyl group of the S 2 CNR 2 − ligand it is induced that 1 is a 2D layered structure, but 2 and 3 are 1D step chain structures. The obtained optical bandgaps indicate that they all belong to semiconductor. Additionally, their thermal stabilities have been investigated.