@@ The trigger of focus intervention effects remains controversial in the Chinese literature: while Soh (2005) shows that focus intervention effects are induced by a focus particle (Foc) alone in Mandarin, Kim (2006) proposes that focus intervention effects are triggered by a focus phrase (FocP) composed of a Foc and a focused constituent based on crosslinguistic data. Our investigation of focus intervention effects in Mandarin reveals that i) the presence of a Foc alone will not induce focus intervention effects as long as the in-situ wh-word (WH) is construed as the focused constituent, as in (1) (Foc is boldfaced and the focused constituent is underlined throughout). ii) Focus intervention effects arise iff the FocP intervenes between the interrogative C (C[Q]) and WH, as evidenced by the contrast between (2) and (3):