Since the academic year 1973-1974, the Republic of China Ministry of Education has assigned 9 senior high schools each year to attempt an experiment on assessment and guidance of senior high school students, aiming to better our senior high school education, and, with the results of this experiment, to improve the total system of the joint college entrance examination. This study was to explore the existing situation of senior high school assessment and guidance and its problems during its excerimentary stage, and to evaluate the benefit that senior high school students get from these activities, so as to search for effective renovations for the guidance activities in senior high schools. This study adopted questionnaires as the major instrument of investigation. The subjects were 1030 graduates-to-be from the 9 experimentary senior high schools. Fifty experimentary senior schools are sampled for the investigation of the present situation of guidance activities. From toth these surveys, the researcher gathered necessary data, undergoing the statistical processes of chi-square and analysis of variance, for the examination of different situations resulted from variables such as sex, group (natural science or social science), further studying or not, and the Farents' educational levels. The major findings are as follows: 1) All schools under investigation have realized various guidance activities, in accordance with the instruction of the Ministry of Education. But owing to insufficient professionals in guidance, difficulties in communication, and the incompleteness of the guidance system, there is the room for improvement in guidance activities. 2) Evaluation of students' guidance activities shows that to most students guidance activities have not ideally been satisfactory. They responded to the effectiveness of guidance with "of no help" and "of little help", only very few of them with "of some help" and "of great help". 3) Guidance activities are more helpful to boy students than to girl students. 4) Guidance is more helpful to those students in the group of natural science than that of social science. 5) Among the various guidance activities, learning guidance, especially in helping students to pass the joint college entrance examination, is more significantly effected than living guidance or vocational guidance. Based on these findings, following are our recommendations: 1) To terminate the experimentary stage, getting ready for an overall realization of guidance activities; 2) To clarify the qualifications of professionals in guidance; 3) To complete the administrative system of guidance; 4) To set up programs for training guidance professionals; 5) To establish an integrative guidance system, for the completion of guidance activities for education in various school levels; and 6) To make researches and develop the theories and methodologies in guidance.