Today, the need for customer trust in banking is inevitable. This research is considered in terms of purpose in the category of applied research and in terms of the nature of a descriptive-survey research. The statistical population of this study consists of customers of electronic banking of Kosar Financial and Credit Institution. Cronbach's alpha for the whole questionnaire is 0.992, which can be evaluated as the reliability of the questionnaire. In this research, a model is presented that examines the effect of online trust of e-banking customers of Kosar Financial Institution on the market share of this institution. In order to develop this model, after conducting library studies, several factors that lead to customers' trust in e-banking were identified and their relationships were considered. Based on this, a model was proposed in which the mentioned factors were divided into two categories of public and private characteristics of online trust and finally the impact of these factors and online trust on the market share of Kowsar Institute was investigated. By collecting and analyzing the opinions of e-banking customers of Kosar Institute by means of questionnaires and data analysis and examining the relationships between variables by SPSS and Amos software and structural equation model, finally the effect of some of those factors and online trust on the market share of the institution Confirmed.