Objective:To build up discriminatory formulas for TCM Syndrome Differentiation Type(TCMSDT) of Aplastic Anemia(AA),discuss ??T subset and their relation with discriminatory formulas.Method:Under the cytometry technique,immuno-indexes in peripheral blood of 34 AA patients and 34 healthy persons were detected.Then build up discriminatory formulas to quantify TCMSDT of AA,and to analyze relations between the subset and TCMSDT.Result:Firstly,absolute value of CD45RA~(+),CD3~(+)CD25~(+) and CD3~(+)HLA-DR~(+),CD3~(+)CD25~(+)(%)and CD4~(+)??T(%)are singled out to make up discriminatory formulas,the total correct ratio is 76.5%.Secondly,vs.control,CD4~(+)??T(%)is statistically in deficiency of kidney-yang group(P