today, the route for economic development in most countries is the same as international open competitive economy. economic institutes well known that supportive public economy belonged on the past and they may compete in the global economy. it is obvious that if they have no competitive potency or not familiar with competition technique, they may be devastated. banking system aims to collect the caught funds and direct them towards economic activities and finally profit making. today, by developed competition, by providing the electronic services, banks use their financial and human resources for fees and profit making services. this study aims to investigate the effect of foreign exchange activities on profit making of bank of sepah to obtain numerical results in order for analyzing the situation of performance of this type of services. to evaluate the foreign exchange activities, we divide it into two main parts including opening l/c and other foreign exchange services including drafts, money orders, and foreign exchange securities and estimate their influence on bank proficiency using virtual variable of banking sanctions by eviews software in econometric and by ordinary limit squares (ols) in the interval of 2002 to 2010 with seasonal data. it is also introduced the foreign resources for financial supply and its effect on bank profitability. results indicate that opening types of l/c and other foreign exchange services (money orders, drafts, and foreign exchange securities) may significantly and positively influence on the profitability and banking sanctions has significant and negative effect on the profitability of bank of sepah. it was also determined that other foreign exchange services has more economical justification than opening types of l/cs. there was also indicated that the role of foreign financial supply is more considerable in increased profitability in the bank.