Abstract: This study tested the concentration of magnesium 0.4, 0.7, 1.4 and 2.8 meq L-1 on the varieties of strawberry plants Seonhong, Maehyang, Keumhyang and Seolhyang cultivated in inert media. The application of the concentration 0.4 meq L-1 on the whole of studied plants gave the smallest quantity of chlorophyll. However, it was not noted a significant difference between the concentrations 0.7, 1.4 and 2.8 meq L-1. Between the varieties and for the concentrations 0.4 and 0.7 meq L-1, we obtained on the leaves of Seonhong` the highest quantity of chlorophyll. The smallest quantity was registered on Seolhyang. For the concentration 2.8 meq L-1, the greatest quantity was recognized on Maehyang and Keumhyang. We also obtained the smallest quantity on Seolhyang. Concerning the physiological stages, during the first stalk flowering, we noted that the greatest quantity of total chlorophyll was on the leaves of Fruit setting stage. It is followed by the leaves of beginning fruit setting stage and finally by leaves of flowering stage.