Background: The needs of emergency medical service is increasing every year, as the first line emergency medical technician, the stress level is increasing higher graduate.Purposes: The purpose of this study was to understand the stress level and analyze impact factors of Pre-hospital Emergency Medical Technicians (EMTs).Methods: The research time started from Sep. 1, 2012, and ended on Dec. 30, 2012. There were 32 EMTs working on Hisnchu City Fire Departments chosen as sample size. Self-made Stress Questionnaires for EMTs were used as tool, which included personal attributes and 4 dimensions' stress, such as patient stress, resource stress, environmental stress, and physic-psycho stress. Likert scale of five points was used to calculate stress; data was analyzed by SPSS 19.0. Cronbach's α reliability of total questionnaires was 0.971. Content and face validity were used.Results: The results showed that average scores of stress for EMTs was 3.53. The highest stress score was Environment Stress 3.63; then, Resource Stress 3.54; Patient Stress 3.40; the lowest stress was Physic-psycho Stress 3.35. Data analysis by ANOVA showed that the marriage status had significant difference with Patient Stress (p<.05). Having children or not, with other duty or not, indicated significant difference with Environmental Stress (p<.05). On Duty or not, health status good or bad, had significant difference with Resource Stress (p<.05). The classification of EMT1 and EMT2 had significant difference with physic-psycho stress. The health situation good or bad, on duty or not, have other service or not, showed significant difference with Physic-psycho Stress (p<.05).Implications: As contribution of this study, it could not only help people to assess the stress level of EMTs, but also indicate impact factors. It may assist EMTs to understand their stress, then, to relieve stress and improve the quality of life.