Grammar teaching has been investigated for different purposes for many years (Ellis, 2006). Since there are students eager to pass some certification tests, required in many colleges in Taiwan in recent years. The research intends to find out what grammar problems the students have, and to look into if the mechanically repetitive practice on similar question patterns help the students better understand the ways of answering the grammar questions in an intensive class. In addition, this research also aims to find whether the students' performance is influenced by their attendance to the class. In other words, if the students attend the class more, they will progress more in the certification test. The data were analyzed by SPSS to examine (1). if the students improved in the grammar section after taking the intensive class, and (2). the correlation between the students' improvement and their attendance. The result showed that the students obviously improved in the performance of grammar section, and the correlation between their improvement and attendance has a significant difference. However, there are still problems on whether they elevated abilities in Grammar or they learned only enough skills to do the certification test.