To better develop silver nanoparticles with good physicochemical properties and bioactivities. Mulberry leaves silver nanoparticles (ML-AgNPs) were prepared from aqueous mulberry leaves extracts (MLE) by green synthesis method. The factors affecting the formation of ML-AgNPs such as concentration of AgNO3 solution, reaction temperature, volume ratio of MLE solution to AgNO3 solution, pH of MLE solution and reaction time were investigated. The products were characterized by UV-Vis, SEM and FTIR. The antimicrobial activities of ML-AgNPs were assessed by determining the inhibition zone and minimum inhibitory concentration (MIC) values, and their anticancer activities were evaluated by cell cytotoxicity assay. The results showed that the optimal conditions for the synthesis of ML-AgNPs were as follows: AgNO3 concentration 5.0 mmol/L, V(MLE)∶V(AgNO3 solution)=1∶5, reaction temperature 35 ℃, pH of MLE solution 11.0, and reaction time 6 h. Under the above-mentioned conditions, the synthesized ML-AgNPs were spherical with an average particle size (48.78 ± 0.39) nm and low surface potential (-27.8 ± 2.00) mV. Compared with MLE, ML-AgNPs showed excellent antimicrobial activities against E. coli, P. aeruginosa, S. aureus, B. subtilis and C. albicans with corresponding MIC values of 12.50, 25.00, 25.00, 100.00 and 100.00 mg/L. Moreover, ML-AgNPs exhibited good anticancer activities against Hela, HepG2 and MCF-7 cell lines with IC50 of 60.63, 26.98 and 18.65 mg/L, respectively.