本研究採用1995至2013年美國公司之顧客與供應商間之關係、避稅與崩盤風險資料並探討顧客公司的避稅活動是否會藉由供應連傳遞致供應商公司導致供應商公司之股價崩盤風險。研究發現顧客公司避稅變數與供應商公司之崩盤風險呈現正相關,表示顧客公司之管理當局透過避稅活動隱藏負面資訊,而顧客公司的負面資訊會由供應鏈傳遞給供應商公司,一旦顧客公司的負面資訊達到臨界點時釋放至市場則導致供應商公司的股價崩盤風險。公司進行避稅之觀點源於代理問題,管理當局與股東間利益不一致所產生使得管理當局會透過財務報表傾向隱藏這些有損股東利益的負面資訊。這些負面資訊會不斷的累積到一個臨界點時,所有負面資訊公諸於世,則造成股價崩盤。再者檢驗不同的盈餘管理變數與避稅變數在不同情況下是否會影響顧客公司之避稅活動透過供應鏈傳遞至供應商公司並使供應商之股價崩盤風險。發現顧客公司在不同盈餘管理變數與避稅變數的情況下亦與本研究之主要結果一致。;This paper employs scale of samples of U.S firms for period 1995-2013 and discusses whether the tax avoidance of customer-firm will lead to firm-specific stock price crash risk of supplier firm. We provide the evidence that tax avoidance of customer-firm is positively associated with supply firm of firm-specific stock price crash risk. It indicates that tax avoidance of customer facilitates managerial bad news hoarding activities for extending these opportunistic behaviors. Then the bad news hoarding activities will promote the diffusion of tax avoidance from customer to supplier. When the accumulating hidden bad news of customer-firm overwhelms a tipping point, the hoarding and accumulation of bad news for extend periods lead to stock price crashes of supplier firm. However, the tax avoidance view overlooks modern corporations: the separation of ownership and control which may cause the manager and shareholder’s inconsistent interests. Managers will use financial statement to hide the bad news. When the bad news will cross a tipping point, it leads to stock price crash risk. Moreover, we displayed that the different earnings management and tax avoidance to investigate tax avoidance of the customer and supplier stock price crash risk. We also found tax avoidance of customer will result in the stock price crash risk of a supplier in different earnings management variables and tax avoidance variables through the supply chain to affect supplier’s tax avoidance.