A kind of biomimetic polymer-inorganic hybrid microcapsule with an egg-like hierarchical structure was prepared via a one-pot method by adding droplets of CO(3)(2-)-containing sodium alginate (enzyme-containing or enzyme-free) into Ca(2+)-containing gelatin solution, in which the formation of an alginate/gelatin membrane around droplets of sodium alginate was coupled with in situ precipitation of a calcified shell. Yeast alcohol dehydrogenase (YADH) was encapsulated in the hybrid microcapsules with about 60% lower enzyme leakage, compared to that of the non-mineralized microcapsules. Meanwhile, the encapsulated YADH exhibited significantly higher thermal stability, recycling stability and storage stability as well as a broader temperature range than the free YADH counterpart. (c) 2008 Elsevier Ltd. All rights reserved.