Abstract: Complex traits are features whose properties are determined by multiple factors ,which can be genetic or environmental, and whose inheritance does not follow the simple rules of Mendelian genetics. Most human complex diseases and most economically important traits in plants and animals are complex traits. The molecular basis of complex traits is theoretical and applied important for genetic improvement in plant and animal breeding. We summarized the conception and research background of complex traits and reviewed the strategies identifying genes underlying complex traits. Based on these strategies, the great progress had been made in dissecting genetic basis of complex traits. At last, we also discussed the challenges and possible developments in future research.

Key words: Complex trait, Genetic basis, Genetic resource, Quantitative trait