In the present scenario, the machine size decreases with time spent and price increases with advances. The materials at nano-scale shows peculiar behavior as of their bulk particulates and resulted advanced multifunction properties were adhered by particulates. The type of synthesis techniques and other physical parameters such as calcinations temperature, pH and dilution were responsible for its properties changes and advancements. In present study the Bi2O3 doped Al2O3 Nano particulates were prepared by microwave-modified co-precipitation method at different calcinations temperature. i.e. 200oC, 400oC and 600oC for fixed duration 2 hours. The calcined powder samples were examined by different instrumentation techniques such as XRD, UV-Vis–NIR spectroscopy, FTIR & HRTEM etc. The XRD study reveals that the particulates are nano-sized in the range 26 nm to 38nm at 200oC to 600oC respectively. The crystallite sizes proved its ascending trend with the rise of calcination temperatures. The IR spectroscopy were deployed to check the functional group present in samples and concluded the purity of samples and the IR- peak at 743cm-1, 744cm-1 and 750cm-1 at 200oC, 400oC and 600oC for fixed duration 2 hours respectively and were might be due increase of lattice energy to O-Al-O vibrations however an additional peak were observed in samples at 2000C at around 1015cm-1 and indicated that Aluminum hydroxide was formed at lower temperature and an addition peak were exhibited at position 484 cm-1 and may be attributed by O-Bi-O vibration of Bismuth ion incorporated in Al2O3 nano particulates at lattice sites. The UV-Vis spectra concluded at the sharp peak occurred at about 310nm and shows that the particulates were nano in size and optical band gap at 3.6 eV. The FESEM image shows that particulates are truncated spherical in shape and agglomerated in nature.