This study aimed to understand the tensions in China's national science system as China is becoming a central player in global knowledge production. Publishing patterns and international co-authorship patterns of Chinese universities were utilized to analyse the dynamics and tensions in the national science system. Findings show that China's scientific publishing and collaboration behaviours are embedded in the 'centre-periphery' framework of the global science system, which stimulates conflicts between the rapid growth of English publishing and the need of developing China's local indigenous research. The Chinese national science system is increasingly stratified as it moves from the 'periphery' towards the 'centre' of the global science system. Its integration into the global science system is reliant upon a handful of top research universities and disciplines in the natural sciences and engineering. A tension lies between the universal and open nature of science and the hierarchical global science network.