In situ remediation of heavy metal contaminated soil is extensively stabilized by using chemical released as industrial by products like limestone, red-mud and furnace slag etc. In our study, we tested the effect of red-mud and furnace slag amendments on extractability of cadmium (Cd) heavy metal, phytoavailability by using Indian mustard cv. Pusa Vijay (NPJ-93) and microbial activity of soil after addition of red-mud and furnace slag in soil sample. In situ remediation of contaminated soil by industrial by products was accompanied by increased microbial activity, increase in soil pH and decreased plant uptake of Cd. Soil microbial activity was determined by using microbial parameters like soil respiration, dehydrogenase activity, glucose mineralization and urease test which was found to be significantly increased after red-mud and furnace slag-amended soils. Compared to non-amended soil, only 30% of Cd was detected in red-mud and furnace slag treated soil samples. In the same time, photosynthetic efficiency of mustard plant also increased as compared to non-amended soil.