Our study desired to investigate how miR-34c-3p regulates colon cancer cell proliferation and what is the relationship between miR-34c-3p and EIF3D. HCEpiC (normal human colonic epithelial cells), SW620, HT-29, SW480, and HCT-116 (human colon cancer cells lines) were used in our study. SW620 cells were chosen and divided into blank, miR-34c-3p mimics, miR-34c-3p NC, miR-34c-3p inhibitors, Lv-EIF3D, Lv-NC, and miR-34c-3p mimics+Lv-EIF3D groups. qRT-PCR was used for the detection of miR-34c-3p and EIF3D mRNA expressions. Dual-luciferase reporter assay was performed to investigate the effect of miR-34c-3p on EIF3D. Western blot was performed to detect EIF3D, cyclin D1, and c-Myc expressions. Clone formation and MTT assay were used to measure cell proliferation ability. colon cancer cells had lower miR-34c-3p expression, but higher EIF3D expression compared with HCEpiC. EIF3D mRNA expression was regulated negatively by miR-34c-3p. In the miR-34c-3p mimics group, colon cancer cell proliferation was significantly decreased, whereas c-Myc and cyclin D1 expressions were downregulated. Colon cancer cell proliferation in miR-34c-3p inhibitors and Lv-EIF3D groups was enhanced, and c-Myc and cyclin D1 expressions were decreased. The results suggested that by targeting EIF3D, miR-34c-3p inhibited colon cancer cell proliferation.