Abstract: Soil aggregates are the basic units of soil structure and play a crucial role in soil functioning. Investigating the effects of tillage practices on the composition and stability of soil water-stable aggregates is beneficial for providing a theoretical basis for the development of tillage practices and soil health. A 5-year field experiment was conducted to investigate the effects of no-tillage + straw mulching (NTMS), fallow (AL), and conventional tillage (CK) on the water-stable aggregate composition and stability at 0 ~ 20 cm soil layer in cultivated loessial soils, and the relationship between these practices and soil properties was analyzed. The results showed that the implementation of NTMS and AL significantly increased the aggregate content of > 5 mm particles in diameter, the mean mass diameter (MWD), geometric mean diameter (GMD), and the water-stable aggregate mass of >0.25 mm particles in diameter; but reduced the aggregate content of <0.25 mm particles in diameter and the fractal dimension (D). The composition of soil water-stable aggregates was found to be significantly correlated with soil bulk density (BD), saturated water holding capacity (SM), and capillary water holding capacity (CMC); while the stability of soil water-stable aggregates was significantly correlated with soil organic matter (SOM), erodibility factor (K), pH, and catalase (CA). The seven factors accounted for 92% of the variation in soil aggregate composition and stability, and the importance of these factors was in the order of CMC (33.6%), SM (25.8%), BD (11.4%), SOM (8.71%), pH (5.42%), CA (5.27%), and K (1.86%). No-tillage with straw mulch and short-term fallow practices promote the formation of larger soil aggregates (>5 mm in diameter) and improve the stability of soil water-stable aggregates.