Effects of phonemic vs. allophonic vowel distribution, stress and direction of coarticulation on V-to-V coarticulation were examined in Cantonese and Beijing Mandarin (BM). Cantonese has more vowel phonemes but BM has more allophones. Cantonese should show less Vto-V coarticulation than BM if phonemic contrast determines degree of V-to-V coarticulation. The vowels used were /i a u/ in /pVpVpV/ structures. Phonemic vowel space density did not influence V-to-V coarticulation differentially in Cantonese and BM. Effects of stress and direction were not consistent. Generally, there was more carryover coarticulation, and more coarticulation on unstressed vowels, but exceptions were common. No one factor appears to determine patterns of V-to-V coarticulation in different languages. Other potential phonological influences are discussed.