Abstract: Pulsed photoacoustic methods have been used to study photoinduced chemical and biochemical reactions in solutions. The important developments of the studies have been achieved in basic theories and experimental techniques, which provide direct measurements of the kinetic dynamics and thermodynamics processes of photoinduced chemical and biochemical reactions in solutions. The applications of the methods include the studies of the photoinduced reactions of organic compound, complex and protein molecules of human, animals and plants. The information on the enthalpy and conformational volume changes of the reactions, as well as the lifetimes and quantum yields of the transient intermediate species, has been obtained in rich. In this paper, the main progresses of the related fields are introduced briefly and some problems that need to be studied are indicated.