To investigate the effects of geometric parameters on uniformity of frozen beef thawed by radio frequency (RF), frozen beef samples with 8 different shapes, thickness, bottom areas and placements were thawed in a RF oven (40.68 MHz) respectively for determining the thawing uniformity. Meanwhile, a computer model was established and utilized to predict the thawing rate and temperature distribution of the samples. The predicted temperature distribution showed a good agreement with the experimental results. The general thawing rates of all beef samples are constant and then decreased gradually as reaching the phase change temperature zone. Samples with larger thickness showed a higher thawing rate, but a worse thawing uniformity. For the samples with the same thickness, the larger the bottom area was, the slower thawing rate was. When placed vertically, the cuboid sample was more seriously overheated, and the maximum temperature reached 55.2 ℃, which represented a poor thawing uniformity. The maximum temperature of the cylinder sample was 36.6 ℃ after RF tempering with relatively better thawing uniformity.