This study was aimed to evaluate the quality of ststistic technique used in the thesis of master of Education, especially, on the area of educational psychology. The criteria for evaluating the thesis was drawn from the functions of statistical technique in the research as follows; 1) the relevancy to the research method and design, 2) the adequacy to the data and research hypothesis, 3) the utility for testing the hypothesis, 4) the accuracy of statistical testing procedure 5) the preciseness of presentation of the results 6) the validity of ststistical conclusion 7) the relevancy of utilization of the results 8) the consistency of the results to the research conclusion One hundred and fifty theses(16.4%) were sampled from the 914 theses conducted during the last three decades on the area of educational psychology, by using systematic and judgmental sampling method. The instrument composing with two parts for evaluation was constructed through several pre-tests and corrections, one is consisted of fifteen items for investigating the background information of the thesis about data collection, the other is composed of eight items for evaluating the quality of the statistical method. Special training and education of four research assistants on data collection and rating the thesis was undertaken before main study as a pilot study. The hard data was collected by using the intrument and also descriptive data was obtained during rating the thesis. In general, relatively easy and simple ststistical methods designed to test the hypothesis were used such as t-test, F test. Incomplete usage of F test was found in many cases ommitting calculate Omega square and multiple comparison. The statistical technique of high level dealing with complex research design and many variables was avoided in most cases. On the other hand, the important procedures for improvement the reliability of e data were ommitted to some extent in almost theses. Findings showed no presentation of the index of reliability and its assessment method, small sample size, non commenting on sampling method, simplicity of reseach design, etc. The results of rating said that from 32% to 58% of theses sampled didn't reach the standards across the eight criteria. The adequacy, validity, and relevancy of the statistic method was found as relative ley low in general, and the utility of the method was considered to be seriously low. The weak points of the thesis about statistical logic and applicability of the statstical method can be used as a highlight in educating and advising the student regarding research methodology. This findings should be used to improve the curriculum of graduate school about research methodolgy and statistics, namely rational sequencing the courses on research methodolgy including research design, statistics, and data processing. The course work and independent study of graduate school should be more emphasized on methodological knowledge and practices required for degree acquisition.