Rational construction of two-dimensional (2D) metal-organic frameworks (MOFs) nanomaterials attracts researcher's much attention due to their unique structural merits. Herein, 2D spindle-like pure and Sn-doped Co3O4 porous nanosheets have been synthesized using 1, 4-dicarboxybenzene (H2BDC) as a ligand acid, and via a simple solvothermal method and following thermal treatment. The structure, morphology and composition of the asobtained samples are characterized by XRD, FESEM, TEM, XPS, ICP, AFM, UV-vis-NIR, UPS and nitrogen adsorption-desorption measurement. The results show that Sn4+ has been successfully doped into the lattice of Co3O4. The gas sensing properties of pure and Sn-doped Co3O4 porous nanosheets have been systematically analyzed. The 5 at% Sn-doped Co3O4 sample shows high responses of 70.7-100 ppm triethylamine (TEA) at a relatively low working temperature of 180 degrees C, which are about 11 times than that of pure Co3O4 (6.4). In addition, the 5 at% Sn-doped Co3O4 exhibits rapid response/recovery time (1 s/17 s), excellent anti-humidity properties, good gas selectivity and repeatability as well as superior long-term stability.