the expression level of HOXD-AS1 was significantly upregulated in OS tissues and cells.in vitro assays confirmed that knockdown of HOXD-AS1 suppressed cell proliferation, colony formation, migration, and invasion, and promoted cell cycle arrest at G1 stage and apoptosis in OS cells. in vivo assays confirmed that knockdown of HOXD-AS1 significantly decreased tumor growth in xenograft mice, and decreased tumor size and weight. Importantly, we also showed that knockdown of HOXD-AS1 significantly reduced signal transducer and activator of transcription 3 and its target protein (CyclinD1, Bcl-2, and MMP-2) expression in vitro and in vivo. Moreover, overexpression of STAT3 could reverse the suppression of proliferation ability induced by sh-HOXD-AS1 in U2OS cells.