The addition of superplasticisers along with mineral admixtures like fly ash and slag in concrete improves the strength and workability of concrete at lesser water cement ratios. To get this benefit, the compatibility between cement and admixtures must be studied. SP’s are normally adsorbed on the cement particles and sometimes the adsorption will not be even and slightly unreliable. This is due to the clinker composition of cement and the type of SP’s used. Various combinations of materials including mineral admixtures affect the behaviour of the cement–based system and become incompatible like slump loss, delayed setting of concrete etc. In the present work, four brands of Ordinary Portland Cements are selected and is checked for its compatibility with 4 types of PCE superplasticisers available in the market using Marsh cone test. The results of these tests conducted on the cement paste is analyzed to find out the optimum dosage of superplasticiser for all the four brands. Chemical analysis and XRD analysis is done for the 4 types of cements to study the behaviour. The work concludes that the presence of MgO in ordinary portland cement affects the cement superplasticiser compatibility to greater extent.