This paper investigates the effects of serial acquisitions on labor cost stickiness. We show that serial acquisitions can significantly increase the labor cost stickiness through increasing managerial optimism, agency costs and labor adjustment difficulty, and the labor cost stickiness further damages corporate value. The baseline findings are weaker in firms with better internal control and higher institutional ownership. Overall, this study contributes to the literature on serial acquisitions and cost stickiness, provides a new perspective for the value-destroying effect of serial acquisitions in a typical emerging market.