In Japanese, tense and aspects are generally marked by a change in predicate into a certain form, such as ~te iru form. Apart from indicating tense, ~te iru form is also used to mark various aspects in a sentence. This makes the ~te iru form have various meanings so that Japanese learners often have difficulty or even make mistakes either in translating or making sentences. This study aims to analyze the learners' errors regarding the use of ~te iru form in Japanese sentences containing tense and aspect, as well as the factors causing the errors. This research was conducted using descriptive methods, with tests and questionnaires as the instruments. The sample is third-and fourth-year university students with the JLPT level N3 ability standard. Based on the research results, most errors occurred in the use of ~te iru form as an aspect marker, while only a few errors occurred in the form as a tense marker. The factors causing the error were the students' deficiency of knowledge and understanding regarding the complexity of meaning and usage of ~te iru forms, as well as interference from Bahasa Indonesia as their mother tongue.