• Grassland-based livestock production systems cover large areas in China.

• China is facing degradation of rangeland and has great shortage of forage.

• Five types of mixed crop-livestock systems in China described.

• Improving crop–livestock integration requires S&T and policy supports.

Interactions between crops and livestock have been at the core of the evolution of many agricultural systems. In this paper, we review the development and characteristics of mixed crop-livestock systems, with a focus on grassland-based systems, as these cover large areas in China, and face several challenges. Following the transition from the original hunting and foraging systems to a sedentary lifestyle with integrated crop-livestock production systems some 8000 years ago, a range of different mixed systems have developed, depending on rainfall, solar radiation and temperature, culture and markets. We describe 5 main types of integrated systems, (1) livestock and rangeland, (2) livestock and grain production, (3) livestock and crop – grassland rotations, (4) livestock, crops and forest (silvo-pasture), and (5) livestock, crops and fish ponds. Next, two of these mixed systems are described in greater detail, i.e., the mountain-oasis-desert system and its modifications in arid and semi-arid regions, and the integrated crop-livestock production systems on the Loess Plateau. In general, crop-livestock interactions in integrated systems have significant positive effects on crop production, livestock production, energy use efficiency and economic profitability. We conclude that improved integration of crop-livestock production systems is one of the most important ways for achieving a more sustainable development of animal agriculture in China.