The Mu tianzi zhuan was unearthed in A.D. 279 from an ancient tomb (said to be that of King Xiang [Ai] of Wei) in Ji Commandery (present-day Jixian, Henan). It recounts the western travels of King Mu of Zhou and of his meeting with the Western Queen Mother, and counts as one of the most famous and important of all of China's unearthed texts. There has long been a debate as to the date and nature of the Mu tianzi zhuan's composition: whether it was an annalistic account from the time of King Mu or a later recounting. Although in the twentieth century there was a general consensus that the text was written in the Warring States period and should count as the earliest short story in Chinese literature, nevertheless paleographers pointed out occasional contacts between the content of the text and bronze inscriptions from the time of King Mu. The clearest of these is the mention of Mao Ban, a figure known from the Western Zhou bronze inscription Ban gui. In this study, I examine three or four other names that appear in the text: Jing Li, Zhai Gong, Bi Ju and Feng Li, and argue that all of them also appear as important ministers to the king in recently discovered King Mu-period bronze inscriptions. Based on this, I suggest that the source of the Mu tianzi zhuan can be traced back to the Western Zhou period. How this source was transmitted to the Warring States period is still unclear and requires further study.