This article explores what has happened in the economic and the military sphere between China and North Korea since 2003(the second round of North Korea's Nuclear Crisis and developing its Nuclear weapon). Recently although there have been some difficulties and conflicts in the realms of economic and military security between two countries, this paper basically suggests that Sino-North Korean relations have not yet brought about fundamental changes in the two spheres. At the same time it underscores they have been firmly keeping stable relationship, in spite of North Korea have became a strategic liabilities for Beijing since 2003, especially North Korea's Nuclear crisis. This argument is based on a series of critical grounds. There are some logical grounds. First of all, Beijing's top priority is Pyongyang's survival, that is to say, China's bottom line is stability and peace on the Korean peninsula. So China do not impose lethal sanctions against North Korea, but decide to help North Korea to survive through a lot of economic support. Secondly, China prefers strategic buffer zone to strategic liabilities for herself regarding North Korea's strategic values. Thirdly, because China do not want abrupt collapse of North Korea, so Preference for the two-Korea status quo, so long as China can sustain influence in both, is evident. Fourthly, China is still officially maintaining "The Treaty of Friendship and Cooperation and Mutual Assistance Between the People's Republic of China and the Democratic People's Republic of Korea" as a treaty of alliance in 1961. Fifthly, Judging from recent interviews with Chinese analysts concerning North Korea, most of whom are affiliated with Chinese government think tanks, China would be reluctantly able to live with a nuclear North Korea after nuclear test, although China officially maintains denuclearization of North Korea.