Chitin membranes (3-5 wt.%) were prepared using immersion-gelation and vapor induced phase separation-gelation processes. The influence of the main physico-chemical parameters such as polymer concentration, pH, temperature, and coagulation bath composition on the area shrinkage and on the mass variation of the gel during chitin gelation has been studied. Results have shown that the key parameter was the mass transport phenomena between the polymer solution and the external environment. The slowing-down of the mass transfer kinetics, i.e. non-solvent penetration and solvent extraction, allows the formation of more homogenous gel morphology.