【Abstract】 Objective To observe the efficacy of triamcinolone acetonide nasal therapy after chronic rhinosinusitis (CRS) and its effects on nasal mucosa interleukin 17 (IL17) and eosinophil (Eos) infiltration. Methods 380 patients treated with endoscopic sinus surgery for CRS from February 2013 to February 2017 were included in the study and divided into control group and observation group with 190 cases in each group by the random lottery method. The control group was treated with normal saline irrigation for nasal cavity, and the observation group was given triamcinolone acetonide nasal therapy after operation. The visual analogue scale (VAS) symptom scores, nasal outcome test20 (SNOT20) score, mucociliary transmission rate (MTR) and the expression levels of nasal mucosa interleukin 6 (IL6), interleukin 8 (IL8), interleukin 17 (IL17), and Eos count and the incidence rate of adverse reactions were compared between the 2 groups at 7d t after treatment and 1 course of treatment. Results The positive rates of nasal mucosa IL6, IL8, IL17 and Eos count were significantly lower in the observation group than those in the control group (P＜005), and the nasal mucosa MTR level was significantly higher than that of the control group (P＜005). The scores of VAS all symptoms and SNOT20 in the observation group were significantly lower than those in the control group (P＜005). There was no significant difference between the two groups in the incidence rate of adverse reactions (P＞005). Conclusion Triamcinolone acetonide after CRS can effectively reduce the nasal mucosal inflammatory factors levels and the degree of Eos infiltration, and improve the nasal mucosa MTR, clinical symptoms and quality of life with less adverse reactions.