The Collaborative International Dictionary of English v.0.48:

Liturgiology \Li*tur`gi*ol"o*gy\, n. [Liturgy + -logy.]
   The science treating of liturgical matters; a treatise on, or
   description of, liturgies. --Shipley.
   [1913 Webster]

WordNet (r) 3.0 (2006):

liturgiology
    n 1: the study of liturgies [syn: liturgics, liturgiology]