This study examines how the acoustic input (the surface form) and the abstract linguistic representation (the underlying representation) interact during spoken word recognition by investigating left-dominant tone sandhi, a tonal alternation in which the underlying tone of the first syllable spreads to the sandhi domain. We conducted an auditory-auditory priming lexical decision experiment on Shanghai left-dominant sandhi words, in which each disyllabic target ([tɕi55 dɛ31] “egg”) was preceded by monosyllabic primes either sharing the same underlying tone ([tɕi55]), surface tone ([tɕi53] “machine”), or being unrelated to the tone of the first syllable of the sandhi targets ([tɕi24] “to remember”). Results showed a surface priming effect, but not an underlying priming effect. Moreover, the surface priming did not interact with speakers’ familiarity ratings to the sandhi targets. The results are discussed in the context of how phonological opacity, productivity, and the directionality of tone sandhi patterns influence the representation of tone sandhi words as well as how the lexicality of the primes and the participants’ usage pattern of Shanghai may have influenced the results.