The purpose of this research is to analyze the effect of the announcement of Russia-Ukraine invasion on the market reaction as reflected in abnormal returns and trading volume activity in 7 countries, namely Saudi Arabia, USA, Canada, UAE, Nigeria, Kuwait, and Norway. This research uses secondary data and there are 29 firms of oil and gas listed in each state as a total sample for this research. This research employs the event study method. The event window is 5 days before and 5 days after the occurrence, and the estimating period is 100 days. Normality test analysis and statistical hypothesis testing were carried out in this study. The results showed that there is no significant difference in abnormal returns but there was a significant difference in trading volume before and after the announcement of the event. This result is supported by the results of the analysis based on countries that are not members of OPEC, countries with semi-strong form of efficient market, and countries with weak form of efficient market as comparisons.