The objective of this research was to improve the ability of the seventh grade students of SMP Negeri 1 Sindue Tobata in using simple present tense sentences through substitution drill. The subject of this research was Grade VIIA. The research was classroom action research conducted in two cycles in which each cycle consisted of planning, implementation, observation and reflection. In cycle one, the students got difficulty in understanding what the teacher meant when teaching because he gave them example without explanation into details. The students were trained individually to constuct free sentences by using substitution drill. That is why, the result of cycle one was low. In cycle two, the teacher explained the material into details and gave the students examples in details. The students constructed free sentences by using simple present tense by applying substitution drill. The data of this research were obtained from the results of the test and observation sheet during the implementation of the action. The data were analyzed based on students achievements in two cycles. It can be seen through the progress of the students‟ successful percentage from 17,86% in cycle I to 96,43% in cycle II. It means that the use of substitution drill is effective in improving the ability of the seventh grade students of SMP Negeri 1 Sindue Tobata in using Simple Present Tense Sentences.