Alginate-carrageenan (Al-Ca) complex films were synthesized and characterized. The Al-Ca ratio and the crosslinking agent type were important factors in determining the pore size of the complex film. The pore size decreased with an increasing carrageenan content and was reduced further by a crosslinking reaction with CaCl2. The most uniform and flexibile film was formed at an Al-Ca ratio of 6:4. The degree of swelling of crosslinked films increased with an increasing carrageenan content. With a combination of CaCl2 and ZnSO4, the water content of the film due to swelling was smallest, which was more suitable than with CaCl2 alone. The permeabilities of glucose and dextrans for Al-Ca complex films increased as the alginate content increased, because complex films with a high alginate content had large pores. The partition coefficients of glucose and dextrans for films were in a range of 0.2 to 1.0 depending on the contents of alginate and carrageenan. A 6:4 Al-Ca complex film was most stable in a phosphate buffer solution, indicating that the 6:4 content ratio was suitable to maintain the mechanical strength of alginate-carrageenan chains. (c) 2006 Wiley Periodicals, Inc.