In China, clients of female sex workers (CFSWs) have a low rate of condom use and a high prevalence of human immunodeficiency virus (HIV). However, little is known about the high-risk sexual behaviors of HIV-positive CFSWs.In 2014, 327 CFSWs diagnosed with HIV for 6 months or longer completed a face-to-face questionnaire for a quantitative survey. In addition, 32 HIV-positive CFSWs were recruited to participate in in-depth interviews (18 participated in both, 14 participated in-depth interviews only) to explore reasons for extramarital sexual behaviors and inconsistent condom use. The quantitative data on sexual risk behaviors were analyzed using chi-square tests. Interviews were coded inductively for emerging themes.Among the participants of the quantitative survey, 41.6% (136/327) had sex with regular sexual partners only in the past 6 months, of whom 64.0% (87/136) had consistent condom use; 27.5% (90/327) of the participants had sex with irregular sexual partners in the past 6 months, of which, 46.7% (42/90) had consistent condom use. The qualitative study suggested that HIV positive sero-status, willingness to protect their spouses or regular sexual partners, and lacking a sense of responsibility to protect their commercial and casual sexual partners, influence CFSWs' sexual behaviors.HIV-positive CFSWs continue to practice unsafe sexual behaviors with regular and irregular partners after HIV diagnosis, but were more willing to protect their regular partners. Future interventions targeting HIV-positive CFSWs should not only be confined to sero-discordant couples, but also need to instill a sense of responsibility to protect the commercial and casual partners and reduce the number of concurrent partners.