In this study, an attempt has been made to measure the speed of population aging based on secondary data collected from the Bangladesh Bureau of Statistics (BBS) and international data base (IDB), US census Bureau. Conventional indices and Kii’s index have been applied to measure the population aging of Bangladesh. From the analysis, it is observed that the conventional indices expose an exaggerated degree of population aging. The conventional measures consider arbitrary cut off points as well as certain age categories rather than each category of age structure. The study reveals that the Kii’s index shows less exaggerated degree of population aging or different trend of the aging process than conventional indices. The Kii’s index uses all categories of age structure of population.