Background: Creating a new berberine liposome with high encapsulation efficiency and slow release formulation in the treatment of cancer is a new issue. Therefore, the aim of current study was to develop slow release berberine-containing nanoliposome for delivery to bone cancer cells Saos2. Materials and Methods: In this experimental study, after synthesis nanoliposomal formulation, physical parameters, including size, zeta potential, and drug loading, in liposome were assessed using different techniques. Saos2 cell line was incubated in micro-plates containing Dulbecco's Modified Eagle's medium (DMEM) and FBS at 37˚C and 5% CO2. Cytotoxicity of nanoliposome was assessed using MTT assay. The release of drug from nanoliposome was assessed by dialysis method. P< 0.05 was assumed significant. Results: The size of drug-free nanoliposome and drug nanoliposome (berberine-nanoliposome) was 112.1 and 114.9 nm, respectively. The zeta potential of drug-free nanoliposome and drug- nanoliposome was –16.1 and –1.9 mv, respectively. There was no significant difference between control and drug-free nanoliposome groups regarding viability (p>0.05). The viability of cells in different concentration of nanoliposome containing berberines in Saos2 cell line was significantly higher than that in free berberines (p<0.05). The release of berberine at temperature 37 º C and pH 7.4 showed that approximately 47% of the drug was released in the first 12 hours of study and then the slow release of drug was continued. IC50 value of free berberine and berberine containing nanoliposome was 137.3 and 52.2 µg / ml, respectively. Conclusion: According to these findings, IC50 value of free berberine was 2.67 times more than berberine containing nanoliposome, indicating that nanoliposome containing berberine had more inhibition on growth of cancer cells than free berberine. In addition, the drug release was slow exposing the drug to the tumor for longer time at a lower dose and fewer injections, increasing the effect of the drug on cancer cells.