Objective To detect the size distribution and Zeta potential of LHRH-MPG△NLS/CDK-siRNA nanoparticles,to observe the effect of different solvents on the nanoparticle size,and to investigate the inhibitory effect of nanoparticles on HepG2 cell growth.Methods LHRH-MPG △NLS and CDK2-siRNA were mixed by continuous stirring to form nanoparticles at different N/P ratios (10/1,20/1 and 40/1).The size distribution and Zeta potential of LHRH-MPG△NLS/CDK2-siRNA nanoparticles were detected by dynamic light scattering,and the stability of the nanoparticles in normal saline,10％ glucose and pure water was discussed.Finally,the inhibitory effect of the nanoparticles on HepG2 cells was determined by CCK8 kit.Results The mean size of the nanoparticles was within 200 nm,and the Zeta potentials were (70±5) mV (N/P=10/1),(120±5) mV (N/P=20/1) and (130±5) mV (N/P=40/1),respectively.The size of the nanoparticles in normal saline was significantly increased,which demonstrated that strong electrolytes had a great impact on the nanoparticles size.When nanoparticle concentration was 200 nmol/L,LHRH-MPG△NLS/CDK2-siRNA nanoparticles (N/P=10/1) showed significantly inhibitory effect on HepG2 cell growth.Conclusions The mean size of the LHRH-MPG△NLS/CDK2-siRNA nanoparticles was within 200 nm,which was ideal for cellular uptake.The Zeta potential of nanoparticles revealed that nanoparticles could be stable in aqueous solution,while strong electrolytes would affect nanoparticle size.When nanoparticle concentration was 200 nmol/L,LHRH-MPG△NLS/CDK2-siRNA nanoparticles (N/P=10/1) showed significantly inhibitory effect on HepG2 cell growth.