A new microporous poly(Schiff base) (PSN-3) is constructed from 1,3,5,7-tetrakis(4-formylphenyl)adamantane and 1,3,5,7-tetrakis(4-aminophenyl)adamantane through an A(4)-A(4) reaction. The surface and internal morphologies of porous PSN-3 are examined by FE-SEM and HR-TEM. PSN-3 exhibits a BET surface area of 865 m(2) g(-1) with a major pore size around 0.6 nm. Moreover, PSN-3 can uptake 1.32 wt% H-2 (77 K/1 bar), 13.6 wt% CO2 (273 K/1 bar), 80.5 wt% benzene, and 63.7 wt% cyclohexane (298 K/0.9 bar). The adsorption selectivities for CO2/N-2, CO2/CH4, benzene/N-2, and benzene/H2O are 88, 16, 267, and 19, respectively. The high adsorption capacities and selectivities for gases and vapors make PSN-3 a promising candidate for H-2 storage, CO2 capture, and recovery of organic pollutants.