The present work is mainly focused on the effect of metakaolin on the self-healing and mechanical properties of conventional and lightweight concrete. The combined effect of autogenous and autonomous healing on mechanical and healing mechanisms was determined by the partial replacement of Coarse aggregate by Fly Ash Aggregates. Bacillus Subtillus bacteria was used in this experimental work along with its nutrients. In conventional concrete, 30% of coarse aggregates were replaced by fly ash aggregates and used as lightweight concrete. In these two types of concrete mixes, metakaolin is used as the partial replacement of the cement by 10, 15, and 20% by binder content. Cylindrical specimens were used to test the split tensile strength and healing mechanism and cube specimens were used for compressive strength at the age of 28 days curing. From the test results, it is clear that the 15% replacement of cement by metakaolin showed better performance and satisfactory strength recovery. FESEM and EDS tests were performed on precipitation collected from conventional and lightweight concrete mixes. FESEM and EDS results are clear that the precipitation is in calcite form.