Cement is one of the main ingredients used in the construction industry, which is manufactured on a large scale. The use of large quantities of cement leads to increasing co2 emission and as a consequence, the greenhouse effect. Consumption of wastes and by-products from various sources as supplementary cementitious materials has gained a great deal of importance. Rice husk ash is a carbon neutral green product. Lots of ways are being thought of for disposing them by making commercial use of this. Partial replacement of cement with mineral admixtures improves the performance of cement based materials in fresh and hardened state. Rha is a good super-pozzolan which can be used to make special concrete mixes. The rha has been taken for this present study due to its easy availability and effective pozzolonic properties. Micro particles due to their small size possess unique properties such as high specific area and high activity which in turn increases the compressive strength and bond strength of the paste aggregate interface. Usage of micro particles of rha to replace cement mortar will have a good impact on its properties. The microstructure of a material can strongly influence the physical properties which in turn governs the application of these materials in various fields. In this present investigation, an attempt was made to study the microstructure of rha micro particles using scanning electron microscopy.