Five species of Annona and one species from Artabotrys, Cananga, Polyalthia, and Rollinia were investigated in regard to 11 different allozyme loci. Preliminary studies on small population samples of Annona suggest genetic uniformity in three species and variability within and between populations in two other species. The allotetraploid origin of A. glabra is clearly shown by its hybrid enzyme bands. The genetic distance between five Annona species partly corresponds with their morphological relationships; only A. muricata appears more separated than is suggested by morphology. A comparison of the five genera demonstrates close relationship between Annona and Rollinia. Two enzyme loci are identical within all taxa investigated and possibly may serve as a genetic marker for the family.