Professional competence is the most important indicators and criteria for the social work education. And, the field practicum is the critical issue for developing the professional competence of social work students. But, in Taiwan, the professional competence readiness of the graduates of undergraduate students and the effectiveness of field practicum had been debated for quite a long time. Thus, the researcher tried to solving these puzzles. In this research, a questionnaire included 79 items of competencies that categorized three parts: ethics (32 items), knowledge (28 items), and skills (19 items) had been designed according to the literature review and the focus group interviews, then the questionnaire had been sent out by mail to the educators and practitioners of social work fields in Taiwan. The 489 valid questionnaires were collected from 74 educators and 315 practitioners. For evaluating the effectiveness of field practicum, 47 valid questionnaires were collected before and after the field practicum. And, the frequency, ANOVA analysis, and paired t-test were utilized to answer the questions below: 1.the professional competence readiness of the graduates of undergraduate, and 2.the effectiveness of field practicum over self-reviewing requirement and readiness of professional competence . Also, the researcher provided five suggestions according to the article’s findings which include: 1.to strengthen the social work professional competence readiness of college graduates; 2.to improve the effectiveness of social work field practicum; 3.to establish the solid goals and the evaluation instrument of social work field practicum; 4.to expand the research about the effectiveness of the field practicum, especially utilizing the experimental design; and 5.to form the consensus of educators and practitioners in social work, then to establish the standards, the evaluation indicators, and the standard operation procedures about the social field practicum.