The purposes of this research were to construct the Self-Development Package on Human Relationships for the Academic Department Chairpersons in Rajabhat Institute and to test its efficiency on 90/90 criteria. One hundred and eighty - three chairpersons of the academic departments out of 36 colleges of Rajabhat Institute agreed in the five rating-scale questionnaires that human relationship was the most necessary skill in academic department administration. Thus self-development package on human relationships was constructed and divided into four packets : Principles of human relationships in administration, concepts of human relationships administrative approach, Buddhist concepts appropriate for human relationships, and human relationships and the behavior of academic chairpersons. Each packet consisted of introduction, conceptual frame work, behavioral objectives, contents, references, self-evaluation, packet test and remedial lessons. There was also a final test of the package. Percentage, Arithmatic Mean, Standard Diviation, t-test and efficiency criteria 90/90 were used for data analyses. Three processes for efficiency test were content validation, package try-out and package experiment to twenty-four academic department chairpersons of Rajabhat Institute based on the efficiency criteria 90/90. The research findings were as followed : self- development package efficiency was 86.75/90.71. The first number was closed to the set criteria and the last number was above it. The pretest and posttest score of the experimental group differed significantly at .01 level. These findings showed that the Self-Development Package on Human Relationships was efficient and appropriate for Rajabhat Institutes academic department chairpersons in developing their own human relationships in administration.