Background <p>Doxycycline post-exposure prophylaxis (Doxy-PEP) represents an emerging strategy for STI prevention. Self-administered use of Doxy-PEP has been empirically observed among men who have sex with men (MSM) in some countries, while little is known about current use of it in the Chinese population.</p> Methods <p>An online survey was conducted among MSM in two cities in China. We detected the current utilized situation of Doxy-PEP with descriptive statistics and constructed χ² or Fisher’s exact tests for factors associated with self-administered Doxy-PEP use.</p> Results <p>Three hundred thirteen individuals returned the results of the questionnaire. Most of them under 35 years of age (79.55%), had college degrees (70.61%) and worked in private institutions (36.42%) or were freelancers (24.28%). 34.2% had heard of Doxy-PEP and 12.1% had used it, while 8.31% were self-initiated users. Doxy-PEP self-initiated use behavior was found to be associated with multiple sexual partners (<i>P</i> = 0.013) and HIV PrEP/PEP experience (<i>P</i> &lt; 0.001). 89.47% of the Doxy-PEP users showed interest in promoting it to others in the future.</p> Conclusion <p>Self-initiated use of Doxy-PEP is prevalent among Chinese MSM, and should be taken into consideration for future public health intervention programs aimed at promoting and implementing Doxy-PEP in China.</p>