THORplan is a treatment planning system developed at Tsing Hua University, Taiwan, for boron neutron capture therapy (BNCT) purpose. It is recently developed with user-friendly interface using Interactive Data Language. In this article the accuracy of THORplan is verified by comparing results of Snyder phantom calculation with the analytical model results of MCNP. Neutron source from THOR epithermal neutron beam is used as the source for the calculation. The thermal neutron flux calculated by THORplan is very close to the reference results. SERA overestimates thermal neutron flux by 2-5%. NCTPlan underestimates thermal neutron flux by 4-9% in most locations. The total weighted dose calculated by THORplan is accurate to within 3% except at the tissue interface. SERA overestimates the total weighted dose at depth >1.5 cm by 2-5%. NCTPlan underestimates the total weighted dose by approximately 10% at depth >1cm.