Abstract: Alfalfa is not only an excellent forage worldwide, but is also a symbol of the cultural exchange between China and western regions, being regarded as a dazzling bright pearl on the Silk Road. Although alfalfa has more than 2000 years of cultivation history in China, scholars in pratacultural science, agricultural history, and Chinese history have different opinions on when this plant spread into China. This article reviews the literature and interrelates the time when Alfalfa was introduced in China based on previous studies. We considered the times when Zhang Qian travelled to western regions and when envoys came to China, with an aim to identify similar ideas and explain the differences among the various theories. There are several ancient books that describe the origin and history of alfalfa, but there are opposing views on when it was introduced into China. The proposed introduction times are: 1) 139 or 138 BC, 129 BC, 126 BC, or 119-115 BC; 2) when Zhang Qian visited western regions in 102-101 BC; 3) an uncertain time; 4) after Zhang Qian’s death or another later time. By analyzing the existing texts, we eliminated the first and second proposed introduction times. The third view requires further historical data to confirm when Zhang Qian visited western regions, because there is a lack of direct historical evidence that Zhang Qian brought back alfalfa seeds. It is possible that alfalfa and ‘sweats blood’ (Ferghana) horses entered China at the same time. Further analyses of historical data are required to validate or disprove these theories.