The suppliers of admixture materials suggest the dosage of these materials in concrete. So it’s crystal clear that the precise determination of the dosage should be done while carrying out the design of concrete mixes. In some of the projects or concrete factories, lab units determine the dosage of admixture when carrying out concrete mix design. Sometimes changing the brand of cement is done while there is no changing in dosage of admixture. In this lab study, with applying 3 specimens of Portland cement type II supplied by 3 factories of quite different production technology (& explain), the effect of 2 types of superplastisizer admixture (Normal & Accelerator) was investigated. So, 7 lab concrete mixes were done on every cement specimen;1 mix for samples with no admixture, 3 concrete mixes with 0.8%, 1.1%, 1.5% usage of normal superplastisizer admixture & 3 concrete mixes with 0.8%, 1.1%, 1.5% usage of accelerator superplastisizer admixture. It was tried to prepare concrete mix with the same workability and adjust their slump about 80-85 mm. The reason of choosing the same workability was its simulation with practical activities. Despite the fact that the cement specimens of the 3 systems are different but have the same chemical characteristics, the results showed that technical characterestics of concrete mixes were different. Hence, it is recommended that a new design concrete mix should be presented according to demand and conditions as the brand cement is changed besides the determination of technical charesterctestics of new cement.