Recent studies recognize a great interest in preserving the environment and sustainable development by reducing the carbon dioxide generated from the cement industry by replacing it with environmentally friendly materials. This could be achieved by replacing a part of cement with mineral addition during concrete mixing. In recent years, the incorporation of metakaolin (MK) in building materials is growing and the compressive strength of cement-based composites is maximized with a 20% content of MK. The present paper studies the calcination of local kaolin at various temperatures (400 – 900 °C) and durations (2, 3 and 4 h) to produce MK with a high pozzolanic activity using a Full Factorial Design. Compressive strength (CS) was taken as responses. Analysis of variance (ANOVA) was performed on the test results to analyze the significance of the effect factors and their interactions on the selected responses. The result shows that the increasing of compressive strength was obtained when ordinary Portland cement was replaced by 10% MK and the mortar formulated by the Kaolin calcining at a temperature of 800 °C for duration of 3 hours improves the early age and the long-term compressive strength.