This paper presents the structure and magnetic propertis of rare-earth gamet ferrite nanoparticles R3Fe5O12 (R = Dy, Ho, Tb) prepared by sol-gel method. The single-phase samples were obtained after annealing the gels at 800°C in 5 hours. The average crystallite sizes of these samples are about 40 nm. Lattice constants of samples are the same as bulk values. Magnetic properties of nanoparticles were measured by SQUID (temperature range from 5 to 300 K, maximum field 20 kOe) and VSM (temperature range from 5 to 600 K, maximum field 10 kOe). Spontaneous magnetizations of samples at 5 K were 8084 percent of the values for bulk samples. Curie temperature and compensation temperature are similar to those of the bulk counterparts. High-field susceptibility is larger than that of the bulks in the studied temperature range which was attributed to the contribution of rare-earth ions in the surface layer of the particles. Coercivity of the samples with R = Dy and Ho exhibits anomalies around the compensation point as single and double peak depending on their chemical homogeneity. The coercivity values are in order of kOe indicating single-domain states of nanoparticles.