Due to the strong cooling laser, the cesium cold atoms trapped in a magneto-optical trap are dressed. The dressed splitting was observed arising from cooling laser for the ground state 6S1/2 F=4 and excited state 6P3/2 F′=5 using the probe laser with the wavelengths of 852.3 nm (corresponding to the transitions of 6S1/2 F=4→6P3/2 F′=3 and 6S1/2 F=4→6P3/2 F′=4 of cesium atom) and 794.6 nm (corresponding to the transition of 6P3/2 F′=5 and 8S1/2 F″=4 of cesium atom), respectively, and their spectral properties were analysed. The results show that the dressed splitting for the ground state 6S1/2 F=4 is the same with that for the excited state 6P3/2 F′=5 for the same intensity and detuning of cooling laser, which is consistent with the prediction based on the dressed state theory.