Reading comprehension is the process of understanding meaning of the text. It involves grasping the writer’s word and activating background knowledge to construct understanding about the text. The students need to find what information is stated in the text, and what the writer’s say which is not stated in the text. They often feel bored when they must read a text. There is no sense in their reading activity that causes a problem in their comprehension. They seem too busy when grasping a text, but they do not get a point of the text. In reading activity, they need to focus and investigate the meaning of the text through intensive strategy in learning. In this research, reading comprehension deals with finding the literal and inferential information. KWL (Know, Want, Learnt) is one of learning and teaching strategies for grasping information with good preparation through activating prior knowledge in pre-reading activity. The aim of KWL technique is to motivate students’ comprehension in reading with activating prior knowledge. The purpose of this research is to investigate the effectiveness of using KWL technique on the tenth grade students’ reading comprehension achievement. This research is a quasi-experimental research which employs X MIPA 6 as experimental group and X MIPA 4 as control group. The researcher conducted this research in five meetings, four meetings as teaching in class and a meeting for post-test by online because of covid 19. The data were collected by using multiple choices reading comprehension test. The data obtained were analyzed by using independent t-test formula. It showed that t value is 2.315 which is more than 1.9977 as t table. Also, the significant value is .024 which is lower than .05. Further, the mean score of experimental group is 80.52 and the mean score of control group is 77.1. Based on the result of data analysis, the tenth grade students of SMAN 1 Giri who are taught by using KWL technique achieve better score on reading comprehension test than those who are taught by using group discussion. There are some suggestions for the English teacher, and the future researchers. The English teacher can apply this technique in reading class because the students are able to achieve better score by using KWL technique. In addition, it is suggested that the result of this research can be used as reference or information to conduct a further research on the use of KWL technique through individual project.