The data are presented on distribution of subtypes and rare variants of Pi system for Moscow population. Serum samples were obtained from 210 families of healthy newborn (father-mother-newborn) from several Moscow maternity hospitals. Phenotypes of alpha 1-antitrypsin were detected by isoelectric focusing in ultrathin layer polyacrylamide gel with the range 3.5-6. In this study 5 common PiM subtypes (except M3M3) were found. The observed distribution of Pi subtypes shows a good agreement with the Hardi-Weinberg equation. The gene frequencies of the subtypes estimated for Moscow population were as follows: PiM1-0.7662, PiM2-0.1779, PiM3-0.0398. They did not show any difference from the corresponding frequencies in other European populations. In the course of our studies, some rare phenotypes, such as MS, MZ, FM and IM that were observed in most European populations, were detected. Furthermore, a very rare variant (MT) which had been only once revealed in European population, was found. The total gene frequency of all rare variants was 0.0162.