Investigating of the sex ratio in the endemic population of the shad Alosa macedonia in Lake Volvi indicated that females predominate (62-97%) except in May and June coinciding with the high participation of the oldest age-classes of the females. Examination of the age structure showed that age-class III is dominant. Individuals of 181-230 mm total length formed the main bulk of the samples (60%), the remainder being 111 to 180 mm (37%) and 231 to 250 mm (3%) (only one individual 331 mm).