Background.Rhesus phenotype has been determined in 404 persons which have problems with blood groups identification. Genetic typing of antigen RhD variants was performed in 73 individuals. Objective of the work was to give molecular and serological characteristics of the antigen RhD weak types.Materials and methods.Method of rhesus phenotype determination in direct agglutination test on plane by using of anti-D, anti-C, anti-c, anti-Cw, anti-E and anti-e monoclonal antibodies; gel method of rhesus phenotype determination; methods of genetic typing of RhD; methods of antigen RhD determination in the classic indirect antiglobulin test and in the gel indirect antiglobulin test; method of antigen RhD determination in the saline agglutination test.Results.Serological methods identified 73 red blood samples with the weakened expression of RhD antigen. Molecular methods showed the reasons of weakness of antigen expression. Three RHD*D weak types which are common in Russians (RHD*D weak type 1–3) were identified and for the first time 3 types were found – RHD*D weak type 67, RHD(G255R) and RHD(JVS5-38del4). Serological characteristic of RhD weak types was given. It was shown that combined using of monoclonal antibodies in direct agglutination test and in gel is the most effective serological method of the antigen variants detection. Red blood cells with weak RhD antigens can be recognized by weakness or absence of agglutination with monoclonal antibodies on plane if agglutination in gel was 3+4+.Conclusion.Concrete weak RhD variants can be determined only by genetic typing. Serologically weak antigen variants can be detected by using of at least two series of monoclonal antibodies or by using of two different methods (it is preferable).