This paper reports three studies of bilingual lexical processing, using the semantic competitor priming (SCP) method of Lee and Williams (2001). Study 1 found a trend of within-language SCP effect for Chinese-English bilinguals with both higher and lower levels of vocabulary knowledge. There was also a cross-language SCP effect, but this was restricted to bilinguals with a lower level of vocabulary knowledge. Study 2 found a cross-language SCP effect for Chinese learners of English in the classroom context. Study 3 found both within- and cross-language SCP effects for bilinguals with study-abroad experience as well as Chinese-English classroom learners who had a higher working memory capacity. Those findings are interpreted in terms of a dynamic view of bilingual language selection.