This study is based on the analyses of literature review, questionnaires and in-depth interviews to discuss the relationship on three variables-- junior high school principals'''''''' instructional leadership, school instructional climate and teachers'''''''' teaching effectiveness. According to the results of 672 junior high school teachers'''''''' investigation and 6 junior high school principals interviews, the major findings were as followed:
A. In the respect of principal instructional leadership
a. From junior high school teachers'''''''' perception, principals do not, in particular, emphasize and pay attention to principals'''''''' instructional leadership. For principals, the best dimension is to "develop a supporting environment" and the worst is in "supervising and evaluation teaching".
b. Area, school size, principals'''''''' sex, years of service, age have significant influences on principals'''''''' instructional leadership.
c. For junior high school principals, their understanding and recognition to the term, "principal instructional leadership", are still insufficient. Mostly they are limited in traditional narrow stage for "supervision teaching".
d. Junior high school principals think that instructional leadership should be focused on and developed. However, while working on the idea, they still play the major role of a manager in school administration.
e. The satisfactory dimension of principal whose instructional leadership is better is different from that whose instructional leadership is worse.These two kinds have different focal points and manners on leadership.
B. In the respect of school instructional climate
a. Junior high school instructional climate is positive and correct. For junior high school teachers, the best dimension is "teaching involvement",and the worst is "coherence".
b. Area and school size have no any significant influences to school instructional climate. Teachers'''''''' sex, years of service, age and post do have significant influences to school instructional climate.
C. In the respect of teachers'''''''' teaching effectiveness
a. Junior high school teachers'''''''' teaching effectiveness is good. In their self-evaluation, junior high school teachers have the best performance on the dimension of "good instructional climate", but have the worst performance on the dimension of "teaching plan preparation".
b. School size, teachers'''''''' years of service, age and post have significant influences on teachers'''''''' teaching effectiveness while area and teachers'''''''' sex do not have any significant influences on teachers'''''''' teaching effectiveness.
D. In the respect of relationship on three variables--principal instructional leadership,school instructional climate and teachers'''''''' teaching effectiveness
a. In this study, Lisrel model of principal instructional leadership, school instructional climate and teachers'''''''' teaching effectiveness has good model fit.
b. The stronger the principal instructional leadership is, the better the school instructional climate is.
c. The better the school instructional climate is, the higher the teachers'''''''' teaching effectiveness is.
d. The relationship between "principal instructional leadership" and "teachers'''''''' teaching effectiveness" is negative. Only by way of a good "school instructional climate" does "principal instructional leadership" promote "teachers'''''''' teaching effectiveness".
e. Principals think that instructional leadership has positive meaning to promote teachers'''''''' teaching effectiveness. However, the following unfavorable factors will influence the efficiency of realization. They are the attitude of teachers'''''''' resistance
on principals'''''''' instructional leadership, the ill relationship which the principal and teachers can not respect to one another and communicate well with one another, unfavorable factors on the environment of school and the lack of teachers'''''''' professional teaching or deviated .
According to the conclusion mentioned above, this study gives suggestions to educational administration units, school principals, teachers and studies in the future.