The primary purpose of this study is to investigate the dynamic nature of agricultural production in Thailand during the period 1971 to 1990. An intertemporal generalised Leontief value function in an adjustment cost framework is used to derive a dynamic system of six equations: an output supply equation: fertiliser and hired labour variable demand equations; and operator and unpaid family labour and capital quasi-fixed demand equations for Thai agriculture. The system is estimated using non-linear three stage least squares applying to annual data from 1971 to 1990 for four regions in Thailand. The results provide valuable information on technical change. speed and independence of adjustment of quasi-fixed factors and elasticities of output supply in That agriculture.