The teacher as the foundation of education whose teaching efficiency and students' achievement are inseparable. There are thousands of strategies on how to improve teachers' efficiency, however, how to find a right teaching method suitable for teaching problems is the biggest challenge that the education systems are facing today. People say that outsiders see the best of the game, the teachers usually cannot detect every detail in the classroom during instruction, so it is relatively important how the researcher intervene the scene and offer his/her observation and proper feedback to the teacher. This article proposed the introduction of the effective teaching feedback observation system which was consisted of PETSCOS, with the help by computerized observation system, it was more convenient for researchers to observe, made accurate record when intervention, and the data could be practically analyzed. It is expected that researchers for the future studies can benefit from this system, and the observation can be made more smoothly and effectively.