Science & technology diplomacy becomes much more important under the new situation when facing global challenges, geopolitics and international relations. It uses international science & technology cooperation as the tool of soft power to establish and improve relations with other countries and it can still play a role as a bridge between countries when their direct relationship in difficulty and setback. Science & technology diplomacy functions in three ways including clear considerations of scientific advices in making decisions concerned international relations, diplomatic policies to facilitate international science & technology cooperation and communication, and the collaborative science & technology activities aiming to promote relations with other countries. National interests act as the key drivers for science & technology diplomacy. Both European Union and the United States pay high attention to the role of science and technology in decision-making system and diplomatic policies, from creating the post of science & technology attache in the embassy, nominating the Science & Technology Adviser for foreign affairs, accrediting science & technology ambassadors overseas and financing researches and trainings. Many practices could be used for reference. For our country, we should develop the national strategy for science & technology diplomacy by improving a national consultation system of science and technology, establishing the talent reserve and encouraging to participate in the international research and experience exchange networks for science & technology diplomacy.