In the study of calculus, the concept of limit of function occupies a central role as it is important instruments used in the study of the theory of rate of change, continuity, integral calculus, and differential calculus. Despite its significance, the secondary students hold the inadequate understanding of the limit concepts, more over their concept image of the limit function deviated from the concept definition resulting in the misconception. This study aims to identify the misconception in the limit of function and possible causes of misconceptions. This study was done in two phases, a concept test based on limit of function was administered to all 25 students of Samtse Higher Secondary School. Subsequently, based on the errors and misconception demonstrated by students from the concept test, five students were purposively selected and interviewed to corroborate the finding from concept test to confirm the existence of misconception and its causes. Data from the transcripts, capturing essential and relevant bits of student's responses to each question, was collected.  The data were analyzed and result of the study can be described as follows; it was found that learners only think of the manipulative aspect when solving problems on limits and not of the limit concept, confusion over the concept of the limit and value of function, and ambiguity regarding the formal definition of the limit of function. The possible cause of the misconceptions can be attributed to instrumental learning and lack of the sound knowledge in algebra which is cornerstone to understand the limit concept.