ObjectiveTo summarize the characteristics of traditional Chinese medicine （TCM） syndrome in primary Sjögren's syndrome （pSS） patients with interstitial lung disease （ILD） and to explore associated factors. MethodA survey was conducted and pSS patients who were treated in TCM department of rheumatism at China-Japan Friendship Hospital from December 2018 to April 2022 were included. Tongue manifestations and syndromes of patients were recorded. pSS patients with ILD were classified into the pSS-ILD group and those without the ILD were included in the pSS-non-ILD group. The tongue manifestations， syndromes， and laboratory indexes were compared between the two groups， and logistic regression was used to explore the factors associated with pSS-ILD. ResultA total of 200 pSS patients were included， with 186 （93.0%） females， median age of 57 years， and median disease course of 60 months， of which 44 （22%） had pSS-ILD. In terms of tongue manifestations， pSS-ILD patients generally had dark/purple/stasis tongue， fissured tongue， and tongue with little fluid， thick coating， yellow coating， and greasy coating. The proportion patients with yellow coating was higher in pSS-ILD group than in the pSS-non-ILD group （χ2=4.799，P<0.05）. In terms of syndrome， more than 40% of pSS-ILD patients had Qi deficiency， Yin deficiency， phlegm-dampness， Qi stagnation， and/or blood stasis syndrome. As for Yin deficiency， liver-kidney Yin deficiency syndrome ranked the first. For Qi deficiency， lung Qi deficiency syndrome was most commonly seen. The proportion of patients with lung Qi deficiency was higher in the pSS-ILD group than in the pSS-non-ILD group （χ2=18.667，P<0.01）. As to laboratory indexes， compared with the pSS-non-ILD group， pSS-ILD group had high proportion of anti-SSA-positive patients （P<0.05） and high levels of C-reactive protein （CRP） （P<0.01）， complement C3 （χ2=4.332，P<0.05）， and complement C4 （P<0.05）. Logistic regression analysis showed that pSS with ILD was positively associated with lung Qi deficiency ［odds ratio （OR）=6.079， 95% confidence interval （CI） 2.585-14.298， P<0.01）］ and yellow coating （OR=5.260， 95% CI 1.337-20.692， P<0.05） and negatively associated with low C4 （OR=0.199， 95% CI 0.070-0.564， P<0.01）. ConclusionAbout 22% of pSS patients had ILD， and patients with pSS-ILD generally have Qi deficiency， Yin deficiency， phlegm-dampness， Qi stagnation， and/or blood stasis syndrome. Yellow coating， lung Qi deficiency and C4 level are factors associated with pSS combined with ILD.