Abstract: Objective To analyze the relationship of NLRP3 inflammasome proteins expression in low-grade myofibroblastic sarcoma(LGMS) tissues with the development, metastasis and prognosis of LGMS. Methods The expression of Caspase-1, apoptosis-associated speck-like protein containing a carboxy-terminal CARD(ASC) and NLRP3 proteins in 13 pairs of LGMS tissues and adjacent cancer tissues were detected using immunohistochemical method. The relationship between the expression levels of three NLRP3 inflammasome proteins in LGMS tissues and clinical characteristics were analyzed. The correlations between every two of these three NLRP3 inflammasome proteins were detected using Pearson correlation analysis. Results The average optical density of Caspase-1, ASC and NLRP3 proteins expression in adjacent cancer tissues of LGMS were(0.40±0.01), (0.42±0.01) and(0.37±0.02), respectively, which were higher than those in LGMS tissues(P<0.05); Caspase-1, ASC and NLRP3 proteins expression in cancer tissues from LGMS patients with metastasis or recurrence were lower than those without metastasis or primary LGMS(P<0.05), but three NLRP3 inflammasome proteins expression in cancer tissues were not affected by age, gender or chronic inflammation diseases in the site of cancer(P>0.05). And there was all positive correlation between every two proteins from these three NLRP3 inflammasome proteins in two groups(P<0.05). Conclusion NLRP3 inflammasome proteins are expressed mainly in adjacent cancer tissues of LGMS, which is closely related to the metastasis and prognosis of LGMS patients.