By means of protein electrophoresis of 26 loci, genetic variation and differentiation of 42 species belonging to 17 genera in the Estrildidae were analysed. A genealogic dendrogram was constructed by the UPGMA method, using the values of the genetic distances between the species of the Estrildidae. Intra-specific genetic variation was detected in 26 out of 42 species examined. The average observed heterozygosity of all the species examined was as low as 0.098. The values of genetic differentiation calculated as genetic distance averaged 0.193 at the species level and 0.397 at the generic levels, which were somewhat higher average values than normal amongs birds. The Estrildidae could be divided into two main groups, the Estrildinae and the Lonchurinae. Unlike the current accepted classification, this method proved Amadina and Lonchura pectoralis to be an old separately differentiated group. The Estrildinae is comprised of three groups, the Estrildi, Erythruri, and Amadini, while the Lonchurinae consists of the Poephili, Lonchuri, and Heteromunii. The basic taxonomic arrangement of genera and species agreed with current classification. Within each group, the average inter-specific genetic distance was 0.304 among African Estrildi as against 0.153 for Australasian Lonchuri. This reflects the older specific differentiation of the former group relative to the latter. These results give support to the hypothetical African origin of the Estrildidae with later dispersal to Asia and Australasia.