Atomic theory is a nature of atoms. The theory has change over time. At first, the theory describes as a philosophy of atoms. The structure of matter was not based on experiment. the scientist began to study the relationship between physical circumstance and magnetism than they began to develop different model about atomic structure. Early theory states that matter is made up of small particle which is called atoms. The word atom come from Greek word atmos, which means indivisible. Previous the matter was considering to be able to divided into any small quantity. The process of improvement represents the best known at that time was not the truth. Development of an idea clarification through testing which is shown more understanding of fundamental