Iran and China has always been considered as two ancient civilizations and their relations have been recorded in official Chinese historiography. The author reviewed some pre-Islamic Chinese sources  and has found out that Sogdians were crucial in bonding these two ancient civilizations. In this regard, the Sogdians were the first to transmit the news of the Sassanid Iran to China through land roads. Furthermore, according to Chinese sources the Sassanid Iran was perceived as a Bhuddist land while we know Zoroastranism prevailed at the time, though some Chinese sources scantily mentioned Zoroastrianism. Therefore, this inaccurate image must have been rendered by eastern civilizations (the Sogdians) for the Chinese who due to their immense distance had cultivated their distinct trade, religious, cultural and bureaucratic systems.