Abstract: CK2 is known to be a tetrameric serine/threonine-specific kinase composed of two large catalytic subunits (? and/or ?') and two small β regulatory subunits. The ??subunit contains a protein kinase domain that is homologous to the catalytic domain of other protein kinases. The ??subunit has been proposed to play a complex role in regulating basal activity of the ? subunit. Upon binding to CK2β, CKII? changes activity and substrate specificity. In this paper we sucessfully expressed and purified CK2β protein and subcloned its SiRNA vector for further the functional reseach of CK2.