Using starch gel and polyacrylamide gel electrophoresis, 11 enzyme systems of two-year-old seedlings from 18 provences of Robinia pseudoacacia distributing in the middle Europe and America were investigated. There were 14 polymorphic loci with a proportion of 70.0% in twenty loci. Twelve polymorphic loci in 7 enzyme systems were calculated. In the 12 polymorphic loci, the mean and effective numbers of alleles per locus were 2.733 and 1.794, as well as the mean observed and expected heterozygosities were 0.368 and 0.400, respectively. Fixation index in most of the loci was slightly higher than zero with a mean value of 0.080. The most population genetic parameters (A, Ae, Ho, He) at the Fe-b and Lap-a loci correlated closely with the mean number of the twelve loci, and such relation was not evident among other loci which may be more important. The genetic distance among the 8 provenances in Germany changed between 0.09 and 0.26, while in contrast, that of the 6 provenances in Hungary were very small and most of them were below 0.11. The genetic distance among the provenances in Germany, Hungary and Slovakia varied from 0.09 to 0.24. Among the 2 provenances in America and provenances in Europe, the genetic distance changed from 0.09 to 0.23, which was not higher than the differences among that of the Europe provenances. Genetic parameters and heredity diversities of the 8 provenances in Hungary and Slovakia were higher than those of the Germany provenances. The differentiation coefficient of the two countries changed from 2.92% to 9.97%, indicting that the genetic difference among the provenances in Hungary and Slovakia was smaller than in Germany provenances. Interpopulational differentiation coefficient in Germany provenances was higher compared with that in Hungary and Slovakia provenances. We took a country as one unit of provenance population, and then the differentiation coefficient of the genetic parameters of the four populations, changing between 3.870% and 5.139%, was rather small. This indicated that it was not evident for the interpopulational geographic differentiations of Robinia pseudoacacia. Therefore, it is suggested that Robinia pseudoacacia has higher genetic diversity and the breeding programs might have been concentrated on intrapopulational variation.