Alvinda Rochmadianti, The Comparison of Financial Performance Before and After Acquisition on Companies Listed in Indonesia Stock Exchange, Thesis in State Polytechnic of Semarang Accounting Department, under the guidance of Muhammad Rois, S.E., M.Sc., and Dra. Nurul Hamida, M.Pd., August 2021, 103 pages. This research is based on the increasing acquisition activities as a strategy to improve financial performance. However, several previous studies show that acquisition cannot improve the company’s performance. This study aims to examine the impact of the acquisition on companies’ financial performance. The population in this study is 10 Indonesian companies that has done acquisition during 2015-2017. The data analysis technique is Paired Sample t-Test and Wilcoxon Signed Rank Test with IBM SPSS 26 program. The results show that there are no significant difference in liquidity, solvability, profitability, and activity in one year after acquisition but in the second and third year show significant difference for all ratios except liquidity in the second year. The result of Wilcoxon Signed Rank Test shows that there are significant difference for solvability, profitability, and activity for all period after compared to all period before acquisition. Meanwhile, liquidity ratio does not have any different.