In the present study the factors affecting the behavior of online shoppers in using the internet as a shopping channel was investigated to determine the effective factors on customer's orientation for buying via internet. This was done because of the many benefits of e-commerce for customers, enterprise, and society, including speed and ease of doing business. These factors with the use of compiled model combining of two theories of Decomposed Theory of Planned Behavior and Technology Acceptance Model were inspected to access a union prospect for the reception of technology by users. The findings of the study, which was conducted on a sample of 360 Internet customers of Saipa revealed that three variables of perceived risk, subjective norms, and marketing mix are influencing factors on the online shoppers` behavior