The characteristics of permeation and separation of dimethylformamide (DMF)/water mixtures through crosslinked sodium alginate (NaAlg) and NaAlg/clinoptilolite (Clt) composite membranes were investigated by vapor permeation (VP) and vapor permeation with temperature-difference (TDVP) techniques. The effects of Clt content of the membrane, feed composition, permeation temperature, and membrane surrounding temperature on the permeation rates and the separation factors were studied. Permeation rates in VP and TDVP were found 0.03-0.41 kg/m(2) h and 0.10-0.45 kg/m(2) h, respectively. Separation factors were increased up to a certain content of zeolite (%15) than decreased, and higher separation factor was obtained in TDVP method (68.80) as compared to VP. Activation energy of permeation in VP was calculated to be 2.794 kcal/mol for 20 wt.% DMF solution.