This study aims to analyze the use of tense and aspect in academic writing in engineering with a major focus on the use of simple past and present perfect. In general, one of the most difficult items for Japanese EFL learners is the appropriate use of tense and aspect. The previous literature pointed out that ESL learners are often confused about using them. Therefore, the American Psychological Association recommends that the past tense is used when discussing another researcher's work and reporting results, whereas the present perfect is used to describe an action beginning in the past and continuing to the present. Toward this end, the current study analyzed the use of simple past and present perfect using a small corpus compiled from 21 major journal articles in mechanical engineering. The study found that the frequently appearing simple past verbs were "showed," "occurred," "resulted," and "indicated." Additionally, "been" was the most frequently used verb in sentences that employ the present perfect. In addition, more than 90% of the sentences were followed by sentences that use the past participle of general verbs. Therefore, many forms of the present perfect clearly appeared in passive sentences.