In women with autoimmune thyroiditis before the treatment it has been established the prevalence of the antibodies mean level to thyreoglobulin over antibodies level to microsomal antigen. Their ratio is 1. L-tyroxin therapy is accompanied by lowering of only antibodies to thyreoglobulin (in the dose of 100 mkg/day and more — trust worthy). In such condition the antibodies ratio has been decreased to 1 and lower. Such treatment don’t promote the antibodies level normalization.