The objectives of the research were to investigate how KWL Technique can improve students writing hortatory exposition text in class XI IPS 4 of MAN 1 Bandar Lampung and to find out whether KWL Technique is effective to teach writing hortatory exposition text under which writing elements applied. The research was conducted at MAN 1 Bandar Lampung. The population of this research was the students of class XI IPS 4 at that school. This research used one group time series design. It took six meetings with test on each meeting. This applied three topics i.e. computer, internet, and facebook. The indicator of the research dealt with the increase of students‟ mean and students‟ number who passed KKM. Besides, the instrument used in collecting the data was writing tests. The result of the tests indicated that KWL Technique is effective to teach writing hortatory exposition text under which writing elements applied. It could be seen that the increases of mean of topic I, II, and III were 15.42, 14.91, and 16.48. Meanwhile, the increase percentages of students‟ number who passed KKM were 61.97%, 43.90%, and 53.66%. It showed that the increase of students‟ ability in writing hortatory exposition text was good. In addition, KWL Technique improves students‟ writing of hortatory exposition text by three elements of writing namely content, vocabulary and language use.