Dorje Ben, director of the Cultural Relics Research Center of Qinghai Provincial Museum, recently gave an exclusive interview to the China News Agency's "East-West Question" Most of the Persian silver coins unearthed in Xinjiang, Qinghai, Gansu and other places in China belong to the Persian Sassanid era (224-651), which roughly corresponds to the Wei, Jin, Southern and Northern Dynasties, Sui Dynasty of China until the early Tang Dynasty. The Sogdians from Central Asia entered China along the Silk Road and established a trading network.