The present study examines the acoustic and articulatory features of English onset and coda /l/s as produced by native English and Mandarin Chinese speakers in the vowel contexts of /i/, /ɪ/, /e/, / ɛ/, /u/, /ʊ/, /o/, /ɔ/, /ɑ/, /ʌ/, /ɚ/, and /æ/, and via the elicitation tasks of word list and mini dialogue. Four Mandarin Chinese speakers who had lived in Canada for at least one year by the time of the experiment and four Canadian English speakers who were born and raised on west coast of Canada participated in the research. Both groups of speakers were the graduate students studying at the University of Victoria. The experiment took place at the Phonetics Laboratory in the Department of Linguistics at the University of Victoria. An ultrasound machine together with a synchronized microphone was used to record the speech data for analysis. The results showed that for onset /l/, the tongue position of the Mandarin Chinese speakers was more front than that of the English speakers. For coda /l/s, Mandarin Chinese speakers had lower and more retracted tongue position than their English counterparts. ANOVA tests showed that vowel contexts and task formality had limited impact on the acoustic qualities of the onset and coda /l/s produced by both groups of speakers. The results and conclusions from the present study will contribute to a better understanding of the articulatory features of the English /l/s. Mandarin Chinese learners may also benefit from this study in that they could potentially improve their pronunciations and reduce accent.