The shift of the cesium hyperfine transition frequency due to blackbody radiation is investigated. The formulas for calculating the shift are derived, and the shift as well as the uncertainty at room temperature is evaluated. In addition, the effect of the frequency shift due to blackbody radiation on the accuracy of the laser-cooled cesium fountain frequency standard is analyzed. Blackbody ac Zeeman shift at room temperature is calculated to be of 10-15 order, thus should be corrected for the cesium fountain frequency standard in determining the accuracy of the standard. When the blackbody ac Stark shift of cesium hyperfine transition is evaluated by determining the dc Stark effect, the uncertainty in the determination of 133Cs dc hyperfine polarizability constant κ will bring out a fractional frequency uncertainty of about 4×10-16 to the correction of blackbody ac Stark shift. This uncertainty is one of the critical factors governing the accuracy level of the cesium fountain frequency standard. In this connection, more precise experiments to determine 133Cs dc hyperfine Stark shift are desirable.