Abstract: The new Treaty on Prohibition of Nuclear Weapons (“TPNW”) opened for signature on September 20, 2017. It will enter into force in 90 days after getting 50 instruments of ratification. This fact shows that Asia-Pacific is in the forward position to totally eliminate nuclear weapons in the world for the peace, security and human well-being. How to move forward the process of ratifying the TPNW? In order to clarify this question, the author will focus on the following three parts: 1) Asia-Pacific and International Humanitarian Law; 2) Treaty on the Prohibition of Nuclear Weapons – a step towards the nuclear disarmament; and 3) Ratification of TPNW.