In the practice of teaching Chinese as a foreign language, shorthanded as Hanyu Jiaoxue or Chinese language (CL) teaching in this paper, the subject teachers are supposed to have a clear understanding of this internally heterogeneous enterprise and equip themselves with some essential internal and external knowledge about the CL. This paper argues that at least four aspects of CL-related knowledge are of great relevance for CL teachers in order to conduct CL teaching smoothly and/or improve the quality of CL teaching. First, a full understanding of the characteristics as well as the core tasks of the CL teaching discipline. CL teaching is inherently the teaching of spoken and written forms of Chinese, and its fundamental purpose is to help Chinese-as-a-foreign-language learners have a mastery of this language. Second, an international vision of CL teaching. Language competency as a national  strength is widely recognized, and the international spread of CL should be viewed as a connection point between China and the world. Third, a clear idea of the interrelation between CL  teaching and cultural education. The teaching of culture should never override the teaching of CL forms. Fourth, an awareness of the variations in ‘broad CL’ and the need for lenient  standardization. Broad CL is congruent with Putonghua (i.e. Standard Mandarin in Mainland China), yet it features some regional variations. In terms of standardization, a dynamic and  tolerant approach should be adopted to cater to the needs of CL teaching in international contexts.