This paper discusses the syntactic and semantic properties of post-verbal durative/frequency phrases in Mandarin Chinese. We have presented several analyses of post-verbal durative/ frequency phrases in the generative literature and pointed out that none of them can correctly predict the syntactic distribution which is affected by both aspectual suffixes and the referentiality of objects. Furthermore, we have examined some syntactic and semantic similarities between post-verbal durative and frequency phrases that are ignored in the previous studies. Building on the evidence from ellipsis, semantic scope and parallelism between nominal and verbal domain, this paper provides a unified account that analyzes the post-verbal durative/frequency phrase as the specifier of a functional projection FP between vP and VP. The functional head F contains a [+measure] or [+counting] feature that checks with the specifier. Referential objects occur in the Spec, VP, whereas non-referential objects occur in the complement position of VP.