The purpose of this study was to determine the effectiveness of the exercises of English language grammar instruction on the achievement of the students when it is applied on web assisted. The study had been executed in accordance with the experimental study model. The experiment group of the study has used a web site that was prepared and they made the exercises of English language grammar in the study. For this purpose, the experiment group subjects has activities such as Chat (IRC), writing the message on the discussion board, and playing the games on the web by using the grammar rules besides answering the exercise questions that are on the web. The control group subjects have similar learning activities through traditional learning methods. The data of study was collected by "English Language Grammar Test" (ELGT) and "English Language Attitude Scale" (ELAS), which their validity and reliability has been tested. It was found that the English language grammar achievement of the experimental groups' subjects who made the English grammar exercises on Web assisted was higher than the control groups' subjects who made them using traditional method.