The first stage zoeas of two box crabs, Calappa japonica Ortmann, 1892 and Calappa gallus (Herbst, 1803), are described and illustrated from laboratory-hatched material. The main morphological characters are compared with those of previously described species within the Calappidae. The first stage zoeas of all Calappa species so far described are very similar except in overall size and the number of spinules on rostral spine. However, there are conspicuous differences among the early zoeal stages of the calappid genera.