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<i>Trichinella spiralis</i> maintains chronic infections within its host, involving a variety of immunomodulatory properties, the mechanisms of which have not been completely elucidated. In this study, we found that <i>T. spiralis</i> infection induced strong regulatory T cell responses through parasite excretory&#8722;secretory (ES) products, characterized by increase of CD4⁺CD25⁺Foxp3⁺and CD4⁺CD25^&#8722;Foxp3⁺Treg cells accompanied by high levels of IL-10 and TGF-&#946;. <i>T. spiralis</i> adult worm excretory&#8722;secretory products (AES) and muscle larvae excretory&#8722;secretory products (MES) were both able to activate BMDCs in vitro to facilitate their maturation and to create regulatory cytokines IL-10 and TGF-&#946;. The T<i>. spiralis</i> AES- and MES-pulsed dendritic cells (DCs) possessed abilities not only to present antigens to sensitized CD4⁺ T cell to stimulate their proliferation but also to induce naive CD4⁺ T cells to differentiate to Treg cells secreting IL-10 and TGF-&#946;. The passive transfer of <i>T. spiralis</i> AES- and MES-pulsed bone marrow-derived dendritic cells (BMDCs) conferred the naive mice to acquire the differentiation of Treg cells. <i>T. spiralis</i> AES possesses a better ability to induce Treg cells than did MES, although the latter has the ability to induce CD4⁺CD25^&#8722;Foxp3⁺Treg cells. The results obtained in this study suggested that <i>T. spiralis</i> ES products stimulate the differentiation of host Treg cells possibly through activating dendritic cells to create a regulatory environment that benefits the survival of the parasite in the host.