Elementary preservice teachers’ understanding about the insect molt and metamorphosis was examined. Data were
collected through the paper-pencil test of 448 junior students at a National University of Education. The instrument used was developed by Son(2003) and modified for the test. The results are as follows: First, Only 3.1% of students had a scientific concept on the molt periods in the insect life cycle. Students had an alternative conception that molt occurs either only in the larval period (29.9%) or only in the period from pupa to adult (22.3%). The percentage of the students thinking that molt occurs in the period from larva to pupa was low. Second, 98% of students stated that molt has to do with the larval growth, but 39.1% of students had an alternative conception that molt occurs after the larval growth at each instar. 25.1% had a conception that molt is related with the larval growth, but did not show any further understanding. Third, most students understood the correct meaning of metamorphosis. 34.2% of students had an alternative conception that metamorphosis occurs only in the period changing from pupa to adult, and only a
few thought that it occurs in the period from larva to pupa. 24.8% of students had a scientific concept on the periods in which metamorphosis occurs. Fourth, some students understood the hatching process as molt in the sense that the egg shell is taken off (21.0%), and as metamorphosis in terms of the appearance change from egg to larva (25.0%).Fifth, 35.5% of students selected bees as an insect of incomplete metamorphosis, and 35.3% responded “I have no idea”, showing that they had poor understanding about the insect life cycle.