Objective: To describe the current reporting of pneumonia of unknown etiology (PUE) and factors that affect reporting by clinicians in China using the PUE surveillance system in order to provide a reference for improving PUE reporting rates in the future. Methods: Clinicians were recruited via the Sojump platform and requested to complete an anonymous self-administered questionnaire. Multivariate logistic regression analysis was used to assess factors influencing clinicians' reporting activities. Results: This study showed a low PUE case reporting rate and a poor understanding of PUE reporting among the investigated clinicians. Of the 136 clinicians who had diagnosed PUE cases, multivariate logistic regression analysis results showed that clinicians who had attended in-hospital training were more likely to report PUE than those who had not (OR 4.48, 95% CI 1.49-13.46). Clinicians with an expert panel on PUE in their hospital were more likely to report PUE cases than those without (OR 5.46, 95% CI 1.85-16.11). Conclusions: There is a need to promote and reinforce PUE surveillance system training among medical staff. In addition, PUE testing technologies in hospital laboratories should be upgraded, especially in primary and unclassified hospitals, to increase surveillance efficiency and improve PUE reporting rates.