This paper investigates the tone sandhi phenomena in Changsha. The investigation of bi-tonal and tri-tonal sandhi reveals that grammatical relations play an important role in conditioning Changsha disyllabic tone sandhi. Tone sandhi behaviors observed in a subject-predicate, a verb-object or a verb-complement construction is different from those observed in a modifier-head construction or a conjunction construction. In tri-syllabic strings, tone sandhi application directionalities are by and large insensitive to morpho-syntactic structures and mismatch between grammatical relations and correct operations of tone sandhi is sometimes observed. This paper examines a Chinese dialect whose tone sandhi has been long been ignored. The study of the complex tone sandhi phenomena of Changsha helps test theoretical models as well as broaden our understanding to Chinese tone sandhi.