The Collaborative International Dictionary of English v.0.48:

Sinology \Si*nol"o*gy\, n. [Cf. F. sinologie.]
   That branch of systemized knowledge which treats of the
   Chinese, their language, literature, etc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Sinology
    n 1: the study of Chinese history and language and culture