In this study, the Turkish students' understanding level of electric circuits consisting of two bulbs and one battery was investigated by using open-ended questions. Two-hundred fifty students, whose ages range from 11 to 22, were chosen from five different groups at primary, secondary and university levels in Trabzon in Turkey. In analyzing students' drawings and explanations, both qualitative and quantitative methodologies were exploited. The unipolar model (Model A), the clashing currents model (Model B), the current consumed model (Model C) and the scientist model with current conserved (Model D) determined from the related literature were used to categorize the students' answers. The results showed that the Turkish students have many misconceptions about electric circuits. Also, it is found out that especially Model A was widespread accepted among the students in group 1 (5th grade) and half of the students in group 3 (9th grade) has an understanding of electric circuits as it is in Model C.