One of the controversial issues in English stylistic inversion (SI) construction (e.g., Into the room walked a woman) is the functional status of preverbal PP and postverbal NP. Based on the distributional parallels among the PP, NP, ordinary subject and topic, this paper proposes that the PP in SI has a dual function as a subject and topic, while the NP also has some subject properties that the PP does not have. These mixed functional properties of the PP and the 'double' subject properties of SI are analyzed in the theory of HPSG, especially with the versions recently developed by Sag 1997, Manning and Sag 1999 and Ginzburg and Sag 2001, which posit the notions of the multiple type inheritance hierarchy and dissociation between the argument and valence structures. This analysis claims that the SI construction needs to simultaneously satisfy two general, independent constraints, head-subject-phrase and head-filler-phrase, as well as the construction specific lexeme-level constraint. This view suggests that the English SI construction is an instance of peripheral phenomena whose construction specific constraints are inherited from more general core constraints.