This survey aims to prepare in-class guidance activities program that tends to improve vocational maturity levels of the students at the 9th and 10th grade classes. This research is an experimental work which tends to examine the effects of in-class guidance activities on vocational maturity level of the 9th and 10th level students including pre-test, post-test and modeled-control groups. High school students that are studying at the 9th and 10th grade in Erzurum Mehmet Akif Ersoy Anatolian High School in 2006-2007 education year, constituted the working group of research. 8 number of in-class guidance activities were prepared for applying to experimental group students of 9th and 10th level after the pre-test process. This in-class guidance activities prepared by researchers were applied for eight week period. In this research technique ANOVA with two factors for complex scales was used in order to test the research data. In the research significance level is defined as (p) 0.05. According to ANOVA analysis result at the end of research was found vocational maturity level scale points showing a significant difference in experimental groups' favor from pre-experiment to after.