This study examines the phonation contrast of Yi, a Tibeto-Burman language of Southwestern China with phonation as a phonemic dimension (traditionally described as tense versus lax contrast). The language has seven monophthongs as well as three tones (high, mid, and low). Tense versus lax phonation contrast can apply to all the vowels and two tones (mid and low) in the language. In this study, both acoustic and electroglottographic data were collected with minimal pairs for all combinations of tones and vowels. Extensive acoustic measures were done by VOICESAUCE, including F0, H1, H2, H1-H2, H2-H4, H1-A1, H1-A2, F1, F2, and cepstral peak prominence (CPP); EGG measures were closed quotient (CQ) and peak-velocity (PV). Preliminary data suggest that H1-H2, CPP, CQ, and PV measures can exclusively distinguish the two phonation types. Moreover, EGG data also suggest voice quality interacts with tones, but the patterns vary among speakers. This might due to the different strategies used by speakers to produce the tense versus lax contrast. In addition, formant frequency measures also show salient differences between tense and lax vowels; tense vowels generally have higher F1 than the lax counterparts. All of the facts suggest that phonation contrasts in Yi are realized across different phonetic dimensions.