Nowadays with developments in technology and information, competition among businesses is intense. How to render their brands, products or services in order to attract more attention and to make distinctive features bigger, so people attract to them or tend to buy them, is very important. Furthermore with innovations in technology and Internet developments, E-commerce has grown so much. Regarding this fact, especially advertising on the net has become an important and effective element in E-commerce. So, the title of this research is Clients Behavioral Responses toward Online Advertising: Assessing the role of Trust and Attitude toward online advertising. The research statistical population is all the clients of Iranian Virtual Network. The sample size is 385. The method of sampling is convenience sampling. All data was collected through questionnaire. Alpha cronbach was used to evaluate the reliability of the questionnaire and AVE was used to assess construct validity. It shows that questionnaire has good validity. Data was analyzed through SPSS 16, Warp PLS3 softwares for both descriptive and parametric statistics. The results indicate that there is a positive and significant relationship between attitude toward online advertising and trust toward online advertising. There is also a positive and significant relationship between trust toward online advertising and adclicking, adclicking and online shopping. However, there is no relationship between attitude toward online advertising and adclicking. According to results of this survey, through controlling effective factors on attitude toward online advertising and establishing more positive attitude toward online advertising, customers' trust can be expanded in order to increase their interest for clicking online advertising, so the number of online shopping-which has less cost for companies and customers- will grow.