Cancer is one of the deadliest diseases among other illnesses as an uncontrolled cell division. Liposomal technology has commonly been used in cancer therapy. Chemotherapeutical drugs, genetic materials, different imaging agents can be carried with liposomes. They are preferred by several important characteristics that selective passive targeting of tumors, increased stability and therapeutic index (reducing toxicity) via encapsulation and increased circulation life times with size adjustments. One of the indicator in cell cycle is intracellular pH. The aim of this study is to produce PEGylated alkali liposomes to provide cellular uptake in cancer cells and prevent cell division by changing of intracellular pH. Combination of liposomal technology and alkaline therapy in cancer cells may lead to the development of therapeutic strategies without using any drug to overcome chemoresistance and cell proliferation. For this purpose, alkali liposomes containing sodium carbonate (Na2CO3) solution were prepared and tested their effects on 4T1 breast cancer cell lines in vitro. The cell viabilities were evaluated using trypan blue and WST-1 methods. Pictures were taken for cancer cells to differentiate live and dead cells under different alkali liposome conditions for 5 days. It was found that cell medium containing alkali liposomes up to 3% didn’t affect cell growth. However, cell medium containing alkali liposomes greater than 7% significantly affected the 4T1 breast cancer cell growth and decreased the cell viability to about 40%. It was concluded that PEGylated alkali liposomes were prepared different concentrations to decrease or stop cell division of 4T1 breast cancer cell lines in vitro.