Abstract: This paper aims to explore the syntactico-semantic analysis of English existential clauses from the perspectives of the Sydney Grammar (SG) and the Cardiff Grammar (CG). It is revealed that in SG's transitivity analysis, English existential clauses can be clauses of existential, (attributive or identifying) relational or material processes, whereas in CG's transitivity analysis, existential clauses are clauses of (locational, attributive, directional or possessive) relational or action processes. In terms of thematic analysis, SG takes the existential There as the unmarked Theme, while CG regards There (and be) as the "thematic build-up" and the postverbal nominal group as the "existential enhanced theme", which is realized either by simple Carrier, Process and Destination, Process and Affected-Cartier, or by Process and Affected. SG and CG are basically the same in terms of the interpersonal analysis and the syntactic analysis of existential clauses.