Liposarcoma (LPS) is one of the most common soft tissue malignancies in adults, and LPS is characterized by dysregulation of multiple signaling pathways including MDM2 amplification.MicroRNAs (miRNAs) are involved in tumor progression by regulating gene expression through incomplete complementary pairing with the 3 'untranslated region of mRNAs.In this study, we showed that miR-215-5p could target and promote MDM2 expression, and promote LPS cell proliferation, invasion, and inhibit apoptosis.QRT-PCR showed that the expression of MDM2 was significantly higher when miR-215-5p was overexpressed (2.85 ± 0.48), and dual-luciferase reporter gene showed that the fluorescence intensity ratio decreased in the overexpression group (0.72 ± 0.02), and cell phenotype assay revealed that the proliferation activity increased in the overexpression group, with cell proliferation rates of 104 ± 0.04 (%), 116 ± 0.01 (%), and 120 ± 0.01 (%), increased apoptosis rate (1.47 ± 0.33 (%)), increased colony formation rate (85.10 ± 2.85 (%)), increased cell healing area ratio (30.08 ± 2.00 (%)), and increased cell invasion number (138 ± 3.60) at 24 h, 48 h, and 72 h, respectively; FISH revealed that miR-215-5p colocalized with MDM2, and MDM2 expression increased in the overexpression group, WB suggested that Bax expression decreased, PCNA, Bcl-2, and MDM2 expression increased, and P53 and p21 expression decreased in the overexpression group;These data suggest that miR-215-5p can promote LPS progression through the MDM2-P53 signaling pathway, and targeting miR-215-5p may be a novel therapeutic strategy for the treatment of LPS.