The purpose of this poster is to present the astronomical activities which were held by High School students in Karditsa and the relation of students’ interest in Astronomy. Since 2004, students have participated in several projects in Astronomy, as the observation of Venus Transit on June 8th, 2004, the observation of Sun eclipse on March 23rd, 2006 and the observation of Lunar eclipse on March 3rd to 4th, 2007. Students also participated in “Hands on Universe” project, studying stars spectrums using computers. Under the same project they also studied the use of Doppler Effect, in order to understand the method to discover planets out of our Solar System. The students’ interest seems to increase as they join the activities. They prefer to choose Astronomy in school and join more and more non formal astronomical activities out of the typical school class.