In stress-accent languages such as English and Dutch, pitch accent is used as the primary cue for contrastive focus, a mechanism to indicate correction or emphasis in discourse. A well-known fact about Chinese is that pitch change is used to indicate tones for lexical contrasts. This study examines how an alternative acoustic cue - duration - is used to signal contrastive focus in Beijing Mandarin. In particular, attention is paid to the interaction of accentual lengthening with other known factors that govern segment duration, namely vowel intrinsic duration and a segment’s position in the prosodic hierarchy. Results from onesyllable constituents will be presented to show their conjoint influence.