The purpose of this research is to define and explain how 7th grade students' in Turkey perceive "eawrthquake" concept using phenomenographic research methods. The research group of the study is comprised of 553 7th grade students in four cities (Ankara, Adana, Antalya and Karabuk) in Turkey. The data of the research was gathered by students' completing "I think earthquake means ...", "In my opinion earthquake is ....". statement. After phenomenographic analysis "7 different earthquake definition categories"were determined. 22.6% of the 7th grade primary school students in Turkey who contributed the research defined the earthquake as "destruction of the buildings and death of people", 19.7% "shakes related to the movements of the earth crust and fult line", 19.5% "natural disaster", 13.8% "swinging of the ground", 11.6% "a natural disaster whose effects increases as a result of people's unconscious and insensible acts"and 10.7% as "a disaster whose defects can be reduced by taking the necessary precautions".