An experiment was carried out to evaluate the effects of planting depth and rhizome sizes on below ground growth of licorice (Glycyrrhiza glabra L.) at research glasshouse of Mashhad Unversity in 2001. Factorial experiment containing 2 factors of planting depth (10, 20 and 40‌cm) and rhizome sizes (1,2 and 3 buds or 4,7 and 10 gr) with two replications in completely randomized block design was employed. Development of different variables during growing season including root and mother rhizome dry weight were measured.The highest and the lowest root dry weight (RDW)have been seen in depth of 20 and 40 cm‌, respectively. About 100 days after planting (DAP), RDW increaseed very slowly but thenafter increased faster‌. Rhizome of any sizes in‌ 20 cm, gave the highest RDW‌. Three-bud rhizomes produced the highest RDW and 1-bud rhizome produced the lowest. Mother rhizome dry weight (MRDW) reduced untill 60 days after planting. After 75th day, MRDW has increased and all plants started to fill their mother rhizome and finally rhizome of depth 20 cm produced the highest dry weight. In 160 days after planting, mother rhizomes started to lose their weight‌. 1and 3 -bud mother rhizome produce the lowest and highest MRDW, respectively.