The most dynamic global integration processes are currently taking place in South-East Asia. It is also the arena of competition between the main regional organisation, the Association of South-East Asian Nations (ASEAN) and the People’s Republic of China. Since the early 1990s, both entities have been seeking to secure the position of the leader in regional international relations, while trying to maximise the benefits of co-operation with the other party. Xi Jinping’s concept of peaceful growth and the assumptions of his political thought, according to which Beijing invites other states to participate in the harmonious development of a ‘community of destiny’, have proved to be a tempting alternative to the ASEAN states facing institutional problems. The Kingdom of Cambodia is an example of a country particularly vulnerable to Chinese influence. This country is referred to as ‘China’s greatest friend in the modern world’, and the events of recent years related to the problem of security in the South China Sea together with economic, political and cultural factors have shown that this alliance, which is asymmetrical in terms of the potential of both sides, affect stability and lead to the erosion of trust within the organisation. The article is devoted to the review of Chinese-Khmer relations in the context of their significance for ASEAN integration processes, particularly in the sphere of security. The article discusses the reasons why Phnom Penh is drifting more towards closer co-operation with China and shows the internal effects of such a unilaterally oriented foreign policy. It also explains the role that Cambodia and ASEAN play for China in their concept of growth oriented towards the international environment.