The Japanese Maritime Self Defence Force (JMSDF) is the naval warfare branch of Japan and a part of Japanese Self Defence Forces which sees its main objectives as protecting the Japanese territories and interests. It is one of the strongest navies in the world.

During the Second World War, Japan’s maritime force was known as the Imperial Japanese Navy which was dissolved after the defeat of Empire of Japan in WW 2. Japan had no maritime security force from 1947 to 1954. It depended on U.S for its protection.
Japanese Maritime Self Defence Force (JMSDF) was formed on 1st October, 1954, seven years after the Imperail Japanese Navy was dissolved. JMSDF is the 5th strongest in the world after U.S, Russia, China and India.
It has 50,800 active duty personnel. JMSDF has 154 naval ships (including auxiliaries). This also makes it the 5th largest navy in the world. Japanese Navy uses JDS (Japanese Defence Ship) as the prefix for its ships.

Japanese Navy has four helicopter carriers, 18 diesel powered attack submarines, 26 destroyers, 6 corvettes, 6 patrol vessels, 3 landing ship tanks, 10 frigates, 30 mine-counter measure vessels and many other auxiliary ships.
Prime Minister of Japan is the Commander-In-Chief of the JMSDF. Its headquarters is located in Japan’s capital city of Tokyo.