Teacher efficacy for increased preservice student’s qualities is considered as an important element in the educational field. The purpose of this research is to identify the relationship between preservice student’s personality, happiness and the teacher efficacy. The following research questions are needed to execute this research. First is to identify the relationship between preservice student’s teacher efficacy and personality. Second is to study the characteristics of the relationship between preservice student’s teacher efficacy and happiness. Towards this end, this research targeted a total of 300 pre service students, 120 students from the two year-long child education program and 180 students from the three year-long child education program located in Seoul, Gyeonggi and Gwangwondo. The tool used for this research is the modified version of the self-assessment tool to evaluate the personality of the teachers who teach children developed by Jeon Jae-sun(2010) in order to measure preservice student’s personality after this was customized to suit the purpose of this research. To measure preservice student’s teacher efficacy, survey questionnaire was produced by referring to the teacher efficacy tool for the math education, developed by Enochs, Smith and Huinker(2000) and teacher efficacy measurement tool used by Ahn Sang-mi(2002). This tool’s sub questions are comprised of total of 21 questions including 13 questions on the personal teacher efficacy and eight questions on the expected teaching effect. Lastly, university students’ happiness measurement tool developed by Lee Su-yeon(2010) was used to measure preservice student’s happiness. This tool is comprised of a total of 23 questions. The result of this research is correlation among teacher efficacy, happiness factors, and personality factors. This research is meaningful in providing the base data for the teacher efficacy increase program that will benefit the preservice students who will work for educational institutions for infants going forth.