Abstract: With this work, it is aimed to determine geography student-teachers’ conceptual framework through evaluating their answer-words given for the key-concept “population”. And alternative concepts about this matter will also be identified and given at the part of “suggestions to be done”. In this work, qualitative research method was applied. Data were collected with the participation of 67 Geography student-teachers. The free word-association test was used as data collection instrument. Data obtained from the study were subject to content analysis, similar answer-words were gathered together and categories were created by this way. Frequencies of each answer-word and some of answer-words in categories were calculated and given in the text as a table. When the data collected about the key-concept “population” were analyzed, answer-words were divided into 5 categories as “population census”, “population distribution and factors affecting the distribution”, “population mobility”, “quality and quantity of population” and “other concepts”. With this work, it was determined that students’ cognitive structures on the concept of “population” are sufficient. Most of the sentences they founded on the concept of population were scientific and including academic information but at the same time these sentences were superficial and including misconceptions.