This research aims to study factors influencing the adoption of internet shopping by Iranian consumers by integrating task technology fit (TTF) model and the unified theory of acceptance and usage of technology (UTAUT). The statistical population includes consumers in capital city of Iran, Tehran, who have had at least one experience of internet shopping. The data were collected through questionnaire. A total of 400 questionnaires were distributed and 392 usable questionnaires were returned. SPSS statistical software was used for data analysis .The results show that except for effort expectation, there was a significant and positive relationship between other variables (task technology fit, performance expectation, social impact and facilitating conditions) and internet shopping. In addition, the findings also indicated a significant effect of task features and technology features on task technology fit.