Cultivated plants are the most important material basis for human survival and development. Growing global human population and personal demands result in increasing consumption of plant resources. The low genetic diversity of cultivated plants is a key factor that restricts production and quality improvements. Wild relatives of cultivated plants have accumulated rich genetic variations and adaptive traits during the process of long-term adaptive evolution, thus can be used as genetic donors in germplasm innovation and improvement of cultivated plants. However, the persistence and evolution of wild relative populations are threatened by habitat destruction and anthropogenic climate change. This review summarizes the progress of in situ and ex situ conservation of wild relatives of cultivated plants and offers conservation suggestions for wild relatives of cultivated plants based on the current situation in China. Moreover, technologies for the utilization of wild relatives of cultivated plants are reviewed and new insights on the sustainable use of genetic resources of wild crop relatives are also discussed. Finally, the status of conservation and utilization of the main cultivated plants that originated from the Yangtze River Basin are investigated, with four plants of different uses used as representatives.