Objective To observe the expression of long noncoding RNA (lncRNA) C00473 in endometrial carcinoma tissues and its effect on the proliferation ability of endometrial carcinoma cells (Ishikawa cells) by regulating microRNA 15b (miR-15b). Methods qRT-PCR was used to detect the expression of lncRNAC00473 in 20 cases of endometrial carcinoma tissues (research group) and 20 cases of normal endometrial tissues (normal group). The overexpression plasmid (pcDNA3-1C00473), siRNA-C00473, and empty plasmid (pcDNA3.1) were transfected into Ishikawa cells and divided into overexpression group, suppression group, and control group (NC group). CCK8 method was used to detect the proliferation of Ishikawa cells in each group. qRT-PCR and westernblot were used to detect theexpressionof lncRNAC00473, miR-15b and its target gene cyclin D1 (cyclin D1) in each group. Results Compared with the normal group, the expression of lncRNA-C00473 in the study group increased (P＜0.05). qRT-PCR showed that lncRNA-C00473 overexpression and inhibitory effect were significant in Ishikawa cells (P＜0.05). The cell proliferation ability of the expression group was increased, and the cell proliferation of the inhibition group was decreased, and the difference was statistically significant (P＜0.05). The level of miR-15b in the overexpression group was lower than that in the inhibition group, and the levels of cyclin D1 in the overexpression group were higher than those in the mRNA and protein levels. In the inhibition group, the difference was statistically significant (P＜0.05). Conclusion lncRNA-C00473 is associated with endometrial carcinoma, which may affect the proliferation ability of endometrial carcinoma cells through miR-15b/cyclin D1 pathway.