The design of a miniaturized CPW-fed rectangular slot antenna over reactive impedance substrate is proposed. Two-dimensional printed periodic circular metallic patches have been introduced on one side of the substrate for designing of reactive impedance substrate (RIS). Instead of conventional metal plate, arrays of periodic circular metallic patches are introduced as backed material for the lower substrate. The proposed antenna gives 44.77% of miniaturization with an improvement of impedance bandwidth. The slot antenna exhibits moderate gain with acceptable radiation pattern and reasonable radiation efficiency.