Indian Ocean covers approximately one –seventh of earth surface and it is the smallest of the world’s three major oceans. The countries on the rim are home to more than 2.6 billion people almost 40% of the world population. It ranks the busiest routes for the global trade. Yet, in spite of this being the smallest, it has become the most militarily active of the three oceans. It is now rapidly emerging as the both an epicenter of the both global trade and great power rivalry. China which earlier followed near coast defence is now looking for gradual expansion towards protection of China’s far-flung economic interests .PLAN has the world second largest with 290,000 personnel and 62 submarines, of which 11 are nuclear powered one. With is growing economic and military power, China has become assertive in relations with its neighbours .India is In grave danger of nuclear encirclement. While its land borders can be guarded by Indian Army and Indian Air Force. The Indian Ocean region offers a challenge.