The purpose of this study is to investigate the correcting behavior of pre-service TCSL teachers in their one-by-one tutoring. Research objects were pre-service teachers in a TCSL department who were doing their tutoring. Three ways were used for data collection: 1. Video recording of the tutoring process of practicum, 2. Interview of student teachers, 3. Practicum reports done by the pre-service teachers. Five results were found: 1. most pre-service teachers implemented correcting in a good timing. 2. Most pre-service teachers will have auxiliary ways in helping their correcting. 3. Pre-service teachers' correction mainly focuses on phonetic problems. 4. Pre-service teachers' seldom use peer-correction and peer-correction techniques in their corrections 5. Pre-service teachers' corrective feedbacks were few and not clear. Too sum up, pre-service teachers' correcting behaviors are still very intuitive. Three points were suggested: 1. Pre-service teachers' should improve their correction abilities other than just on phonetic problems. 2. Pre-service teachers should implement their correction techniques with good flexibility. 3. To remind pre-services teachers to give proper feedbacks to students after corrections.