Nowadays, banking businesses have grown rapidly which are shown with the establishment of many private banks. The tight competition, either private or public bank, requires the banking actors to improve the service and transaction to be easy, save, effective and efficient. Bank Syariah Mandiri is one of Islamic banks which is famous among the community, andit certainly has many customers; therefore, in order to face tight competition with other Islamic banks, it should really pay attention towards the wishes and needs of its customers. This study used multiple linear regression to discover the effect of an event towards another event quantitatively. There was the effect of perceived usefulness towards behavioral intention in using mobile banking in this study. The effective contribution of perceived usefulness towards behavioral attention was 19.10 % and relative contribution of X1 towards Y was 47.40%. There was an effect of perceived ease of use towards behavioral attention. The effective contribution of perceived of ease of use towards behavioral intention was 21.13% while the relative contribution of perceived ease of use towards behavioral intention was 52.43%. The perceived usefulness and perceived ease of use altogether affected the behavioral intention of the customers in conducting banking transaction. Perceived of usefulness and perceived of ease of use variables altogether had an effect towards customers’ behavioral intention variable in doing banking transaction. The value of R square (determinant) was 0.38 or 38%.