The establishment of market dominance is not illegal as such. It is the abuse of market dominance that may violate competition law. This chapter examines some abusive practices which are closely to the use of trade secrets in China: the refusal to disclose trade secrets, bad faith litigation of trade secrets and non-challenge clauses of trade secrets. By comparing antitrust experience from the US and the EU, this chapter considers characteristics of a trade secret and their implications on anti-monopoly analysis in China.