Based on the published journal articles in the Chinese Science Citation Database(CSCD) in 2017, 621,066 citation records were extracted, and two citation networks of five types and 68 disciplines were constructed to analyze the interdisciplinary knowledge flows of sciences and technologies in China. It is revealed that the disciplines of natural science play fundamental roles; that the disciplines of biological sciences and environmental sciences occupy the core of interdisciplinary interaction networks; that the disciplines of medical sciences and agriculture are all self-contained; and that the natural sciences and engineering are closely connected. While the disciplines similarity in natural sciences is low, there is extremely high disciplinary similarity in agriculture, and mid-similarity in engineering and technology.