This quantitative study investigated Chinese college students' self-identity changes associated with English learning. The subjects were 2,278 undergraduates from 30 universities, obtained from a stratified sampling. Based on existing literature of bilinguals identities, the self-designed questionnaire defined six categories of self-identity change: self-confidence, subtractive bilingualism, additive bilingualism, productive bilingualism, identity split, and zero change. Results showed that in the Chinese EFL context, English learning exerted influence on learners' identities, the most prominent being self-confidence. At the same time, learners values and communication styles underwent some productive and additive changes. Sex, college major, and starting age for English learning had significant effects on certain types of self-identity change. Female students scored higher than male students on self-confidence and productive changes. Compared with natural and social science majors, English majors demonstrated more changes in self-confidence, subtractive, additive and productive changes. With self-confidence change, those who started English learning under 8 scored lower than groups of higher starting ages. With additive change, the 912 group scored higher than the 1315 group. With identity split, the above 16 group scored higher than groups of lower starting ages.