The present invention openly comprises bioactive molecules and is connected to the fusion rotein of immunoglobulin (Ig) (Ig) the Fc structural domain of bioactive molecules.This Fc structural domain is (i) IgG1, IgG2 or IgG4, or the (ii) hybridization people Fc structural domain of IgG4 and IgD.This hybrid Fc is as the carrier of bioactive molecules.