Patmasiriwat and Suewattana (2010), which aimed to obtain the long-term sources of total factor productivity, divided the factors that possibly involved in the total factor productivity in agriculture into three categories: price including both commodity price and input price; quasi-fixed factors2 ; and uncertain climate factors. In studying the connection, they introduced the log-log functional form with recursive structure into the model. Eventually, they found there are seven factors relative to the growth of the agricultural productivity which are education, agricultural capital stock, cultivated land, price of fertilizer, expected crop price, irrigation and agricultural research expenditure, and crop location. For the climate factor, it has no evidence in guarantee the effect of the rain volume to the longterm productivity.