The results of the histological analysis of the Antarctic toothfish (Dissostichus mawsoni) gonad structure, caught in December-February, 2004-2005, by longliner YANTAR in subareas 88.1 and 88.2 of the Ross Sea are presented. The morphological parameters and indices of maturity have been described. The histological criteria of the assessment of the ovary maturity stages, cytological parameters of oocytes and type of the toothfish oogenesis have been determined. The analysis of the histological state of toothfish testes has been made, and the abnormal primary fusion renal and generative tissues in testis have been revealed. It was shown that for Antarctic toothfish during the fishing period the females with ovaries on the early III stage of maturity were dominated (47.0%), and males with testis on III stage of maturity (85.7%).