Abstract: The acid microenvironment of tumor cells is mainly due to the proliferation of tumor cells and the high metabolic capacity，which leads to the stability of the microenvironment and the ability of metabolic acid.They are mainly used to maintain the steady state of their microenvironment by either extruding excess H+ or Intracellular transport of HCO3.The study found that sodium hydrogen exchange 1（NHE1），transport protein of transmembrane，is a widely expressed acidextruding membrane transport protein，upregulation or activation of its expression，which is usually associated with the malignancy of the tumor.This article reviews how altered pH homeostasis，and in particular NHE1，contributes to tumor cell motility，invasion，proliferation，and growth and facilitates evasion of chemotherapeutic cell death.

Key words: tumor microenvironment, sodium hydrogen exchanger isoform 1, cell proliferation, cell migration, cell invasion