Lexical bundles are recurrent multiword combinations and often function as discourse building blocks. Lexical bundles have been analysed in university students' writing to detect linguistic errors, measure writing competence, and investigate the divergence between L1 and L2 writing. Few studies, however, have focused on the high-stakes genre of PhD thesis and investigated the bundle productions of the same genre within the same level and discipline. This paper compares sentence initial lexical bundles in the corpora of English theses written by Chinese and New Zealand PhD students in the discipline of General and Applied Linguistics. Forty-six bundles from a Chinese corpus and forty-two bundles from a New Zealand corpus were generated. Among them, 94% of sentence initial bundles were identified as metadiscursive bundles. Chinese and New Zealand doctoral students showed considerably different preferences in their bundle selection. The paper examines the possible impact of these preferences and suggests there is a need to extend the metadiscourse knowledge of doctoral students in terms of lexical bundles.