Abstract: Aerosol can affect climate by changing cloud characteristics in many ways.As cloud condensation nuclei,aerosol can vary indirectly radiation and precipitation because they change the warm cloud number and cloud lifetime.Those are so-called albedo effect and cloud lifetime effect received most attention recently.Observations,including ground-base and satellite,and numerical simulation are the main research methods,they so for are often applied by coupled together.To understand the research of indirect aerosol effects,this paper introduces the concepts and research methods of indirect effect.Some work done by Chinese will also be mentioned.