New technologies are valuable opportunity for faster and less expensive production in the developing \ncountries. It appears, however, that the relatively developed countries have managed to repeat their \nsuccessful results and enjoy notable improvement by using IT. On the other hand, under-developed \ncountries do nothing but watching the gap between them and the developed world widening. One of \nthe reasons of this widening gap is failure to determine the outcomes of utilizing IT. The present study \nis an attempt to determine the effect of IT on quality of supply chain in knowledge-based firms. Study \npopulation was comprised of all employees and managers of the companies located in Pardis \nTechnology Park, Tehran. To measure utilization of IT, a standard questionnaire with four dimensions \n(process, context, internal texture, and external texture) was used. Given the lack of any \ncomprehensive questionnaire in the field of quality management of supply chain, a researcher-\ndesigned questionnaire was designed based on literature review. The questionnaire covered four \ndimensions of empowerment, learning, continuous development, quality of communications, strategic \nlearning, and innovation process. Standard deviation (SD) of the population was determined through \na preliminary sampling. To this end, the questionnaire was administered among 73 of the individuals \nrandomly. SD of the questions showed that max. SD was 0.401. With this, therefore, sample group \nsize was set to 189 with 5% error level. Out of 200 questionnaires, 171 were returned and used as the \nbasis of statistical analyses. Having confirmed reliability and validity of the two questionnaires, and \nSEM in AMOS, the results indicated that the main hypothesis (effectiveness of IT on quality of \nsupply chain) was supported. So that the effect of IT in non-standard and standard modes was equal \nwith 0.24 and 0.58 respectively. The highest effect in this regard was observed on the dimension \nexternal texture.