This study investigated the phonological preparation unit when planning spoken words with native Chinese speakers who speak English as a Second Language (ESLs). In Experiment 1, native Chinese speakers named pictures in Chinese, and the names shared the same onset, same rhyme, or had nothing systematically in common. No onset effect was shown, suggesting that native Chinese speakers did not use onset as their preparation unit. There was a rhyme interference effect, probably due to lexical competition. In Experiment 2, the same task was conducted in English among Chinese ESLs and native English speakers. Native speakers showed onset facilitation whereas ESLs did not show such an effect until Block 3. ESLs’ phonological preparation unit is likely to be influenced by their native language but with repetition they are able to attend to sub-syllabic units. Both groups showed rhyme interference, possibly as a result of joint lexical and phonological competition.