Gene therapy, as therapeutic treatment to genetic or acquired diseases, is attracting much interest in the research community, leading to noteworthy developments over the past two decades. Nonviral vectors have recently received an increasing attention in order to overcome the safety problems of viral counterpart. Nanoparticles with their special characteristics such as small particle size, large surface area and the capability of changing their surface properties have numerous advantages compared with other gene delivery systems. This article reviews the advances of nanoparticles in patents for gene delivery and emphasizes methods to promote gene transfection efficiency.