The interaction of light with dressed atoms is discussed. Master equations which normally appear as an infinite set of first-order differential equations coupled with each other are simplified to 4 independent equations, leading to Bloch equations for dressed atoms through which all the coherent interactions of atoms with light can be extended to the case of dressed atoms. The susceptibility of the dressed atoms to two probe beams is deduced. The generation and characteristics of the phase conjugation wave in dressed atoms are studied.