Soil aggregates and soil organic matter are inseparable because they are the basic substances that maintain soil structure and fertility. The former is the place where the latter exists, whereas the latter is the cement that keep the former in existence. In the current literature, more reports are available on soil aggregates and soil organic matter, separately than on characteristics of soil organic matter in soil aggregates. This paper is going to present an introduction, from the perspective of physical fractionation combined with chemical fractionation of soil organic matter, to advancements both at home and abroad in researches on quantity and properties of soil organic matter in soil aggregates and their responses to agricultural measures, including fractionation of soil aggregates, quantity and stability of each fraction, quantity of organic matter in aggregates, properties of the unfractionated organic matter and properties of the humus fraction, quantity and properties of the organic matter in each particle-size fraction, quantity and properties of the organic matter in fractions sorted by aggregate-density in combination, impacts of land-use pattern and long-term cultivation and fertilization on organic matter, etc. in order to promote the research on interactions between soil aggregates of different particle sizes and different humic fractions and their contribution to soil carbon fixation and soil fertility, to explore relationship between the physical protection and chemical protection of soil organic matter and provide a basis for exposing mechanisms of soil carbon sequestration and build-up of soil fertility.