Abstract: Objective To evaluate the effectiveness of Tianjin front line field epidemiology training program（TJFETP） which the grassroots epidemic prevention and control capacity improvement project carried out two phases in 2021，understand the problems and needs，and provide reference for the future carrying out the front line field epidemiology. Methods The students who participated in TJFETP in 2021 were selected as the survey object. The basic information of the trainees，their satisfaction with the training work and teachers，their knowledge before and after the training，and their ability improvement before and after the training were collected through questionnaires，to evaluate the effectiveness of training. Results The trainees' overall satisfaction with the theoretical teaching was 98.30%，satisfaction with the schedule was 94.87%，satisfaction with the content was 98.30%，and satisfaction with the teaching form was 98.29%. The satisfaction with theoretical teachers was 97.32%，with the practical teachers was 97.44%. The scores of tests in different stages increased from （66.85±14.90） and （71.79±8.70）points before training to （77.95±11.74） and （74.23±6.23）points after training. The defense score increased from （73.59±10.06）points in the preliminary defense to （80.18±2.96）points in the formal defense. Among the five core competencies，the awareness of making public health policy based on the results of monitoring analysis increased from （4.69±1.56） before training to （7.41±1.77）points，the ability of collecting，analyzing and interpreting monitoring data increased from （5.64±1.58） to （7.69±1.59）points，the ability of improving the quality and utilization of disease and outbreak surveillance data increased from （5.31±1.45） to （7.69±1.66）points，ability of sharing and dissemination the public health information increased from （4.87±1.58） to （7.49±1.67）points，and the ability of responding to case investigation and outbreak investigation of public health events increased from （5.54±1.79） to （7.85±1.66）points. Conclusions The front line field epidemiology training is beneficial to improve and supplement the field epidemiology training system in China. The front line field epidemiology training in Tianjin has a good effect，which plays an obvious role in improving the field epidemiology ability of professional and technical personnel in local centers for disease control and prevention.

Key words: Field epidemiology, Training, Evaluation on effect