Objective To explore the signal transduction pathway of calcium-sensing receptor (CaSR) mediating hypoxia-induced proliferation of A549 cells of human non-small cell lung cancer. Methods The A549 cells were randomly divided into several groups which conclude control group, hypoxia group (H), hypoxia + CaSR agonist group (H+Gd), hypoxia + CaSR inhibitor group (H+NPS) and phospholipase C(PLC) pathway inhibitor group (H+Gd+U73122). Expression of CaSR and proliferating cell nuclear antigen (PCNA) in A549 cells under different treatments was analyzed by Western blotting. The changes of intracellular calcium ion concentration were detected by confocal laser scanning microscope. The effects of cell proliferation cycle and proliferation index were gauged by flow cytometry under different drugs. HE staining was used to observe the changes of cell number with different drugs. Results The expression levels of CaSR and PCNA in A549 cells increased by hypoxia. Meanwhile, cell proliferation index and cell number were also upregulated. GdCl3 (CaSR agonist) could amplify the effect of hypoxia, and NPS2390 (CaSR inhibitor) could reduce the effect of hypoxia. All effects mentioned above could be inhibited by U73122 (PLC pathway inhibitor). Conclusion Hypoxia-induced CaSR can mediate the proliferation of A549 cells through Gq-PLC-IP3 signal transduction pathway.