[영문]The most visible output of the European Union (EU) negotiation process is shifts in actors' policy positions. Shifts in actors' positions have relevant implications for understanding the EU decision-making process. On the one hand, actors' shifts in positions can be interpreted as evidence that negotiation actually has taken place. On the other hand, shifts in positions imply that there is a tendency to compromise for convergence upon a final solution. This article indicates the extent to which institutional factors and negotiation conditions can explain those shifts in actors' positions. A subset of the DEU dataset containing information on shifts in actors' positions on issues raised by 28 Commission proposals is examined. The research shows that shifts in positions can be explained by institutional factors such as the decision rule and the legislative procedure implemented, the voting power actors hold in the decision-making process and/or the type of policy instrument executed.