Abstract: This study aims to describe the effect of information technology-based game media on critical thinking skill of fifth graders on social studies subject under the theme of the Indonesia’s struggle for independence. The research subjects were 26 fifth graders of SDN Lakarsantri III/474 Surabaya, 2018/2019. The research subjects were divided into 2 groups of control and experimental groups. Data collection was carried out through tests, observations, and validation of learning devices with information technology-based game media. Information technology -based game media significantly affected students critical thinking skill. This result is based on Normalized gain (N-gain) or Gain Score and t test. The results of the Gain score calculation for the experimental group indicated an increase in students critical thinking skills of 0.81 (High). T test analysis resulted in the Sig. (2-tailed) of 0,000 with a significant level of 0.05. in conclusion, information technology-based game media had a significant effect on students critical thinking ability.