BackgroundFear of progression is one of the typical psychological consequences in patients with chronic obstructive pulmonary disease （COPD）. The level of fear of progression is affected by the illness perception status， and the link between social support and fear of progression is acknowledged， whereas the mechanism underlying the three remains unclear due to the lack of empirical research evidence and needs to be further studied. ObjectiveTo explore the mediating role of social support in the relationship between illness perception and fear of progression in COPD patients， and to provide references for effectively alleviating fear in COPD patients. MethodsA total of 435 COPD patients admitted to the Department of Respiratory and Critical Care Medicine， the Affiliated Hospital of Southwest Medical University from March 9 to July 31， 2024 were selected as the study objects. The Chinese version of Fear of Progression Questionnaire-Short Form （FoP-Q-SF）， Chinese version of Brief Illness Perception Questionnaire （BIPQ） and Social Support Rate Scale （SSRS） were used for the evaluation. Pearson's coefficient was calculated to assess the correlation among above scales. Model 4 of the Process macro 3.4.1 for SPSS 25.0 was used to test the mediating effect of social support on the relationship between illness perception and fear of progression， with Bootstrapping used to evaluate the significance of mediating effect. ResultsA total of 412 patients （94.71%） completed this study.BIPQ score was positively correlated with FoP-Q-SF score （r=0.238， P<0.01）， and negatively correlated with SSRS score in COPD patients （r=-0.260， P<0.01）. FoP-Q-SF score was negatively correlated with SSRS score （r=-0.271， P<0.01）. Social support mediated the relationship between illness perception and fear of progression， with an indirect effect value of 0.025 （95% CI： 0.009~0.041）， accounting for 13.02% of the total effect. ConclusionIllness perception can affect the fear of progression in COPD patients both directly and indirectly through social support. ［Funded by Nursing Research Project of Sichuan Province （number， H22010）］