This paper develops Davis technology acceptance model by adding two criteria of e-readiness assessment. For small and medium size enterprises, the paper evaluates the credit of developed model in studying the efficient factors in internet technology acceptance, which is one of the most applicable communication tools in e-commerce. The added factors, taken from models and means of e-readiness assessment, are “existing information technology infrastructures” as well as “organization’s training”. The authors study 45 small and medium size enterprises in the city of Tehran, which are active in information technology products and services. Using Lisrel structural equation modelling, it is shown that there is a meaningful relationship between the added factors and the variables indicating internet network usage. Therefore, the better factors of e-readiness assessment lead to the higher acceptance level of electronic communication tools in e-commerce.