The Chinese National Compound Library (CNCL) conducted its first structure duplicate check and exclusion between June 17 and 18, 2014. Twelve representatives from CNCL core facility and six satellite libraries gathered in Zhangjiang, Pudong and performed duplicate check on their respective sample structures with the Inforstack software. After exclusion, the number of small molecule compounds collected by CNCL and its six satellite libraries exceeds 1.37 million.