In this dissertation, the researcher investigates (1) the differences between ordinary accounting standards and business taxation in the Kingdom of Thailand (Thailand) and those specifically characteristic of the leasing business. Furthermore , the researcher identifies (2) factors that have affected accounting and taxation in the leasing businesses such that they remain small scale businesses with laggard growth rates, thereby concomitantly affecting the overall economic development of the leasing business. Finally, the researcher constructs (3) a model for leasing business accounting and taxation practices and conditions in accordance with which these businesses would accrue benefits by virtue of being in closer congruence with ordinary accounting and taxation practices and conditions in Thailand