Rubber has been grown in South ern Thailand for many decades. Now a day the rubber sector faces several challenges such as land use changes, labor constraints, and price fluctuation inducing changes in the structure of the agricultural system. The aim of this paper is to analyze how Thai rubber farms evo lved in this changing environment. A purposive sampling household survey of 393 rubber owners and interviews of key informants from four r epresentative villages in Songk la and Patt h alung provinces provided data for analysis. We established and characterize datypology of rubber farm trajectories since 1990. For that, we adopted an innovative method using two sequence steps: multivariate analysis and the repeated clustering technique. We found that six farm trajectories can be identified using the evolution of farm structure. Stability of family farms 38.2% of farms) showing no evolution of the farm size and labor use, is the trajectory gathering the largest proportion of farms for the past 20 years. High structural change of the farms (10.5% of farms) and d eclining very small farms (25.0% of farms) are constituted by farms that experienced a decrease in the size of the landholding and limits to expansion. In opposite, three trajectories, namely the growth of large family farm enterprises (4.1 %), the growth of medium family farm enterprises (14.5%), and toward patron farms (7.7%) are composed of farms with a continued expansion in landholding and hired labor use. These six farm trajectories show that a polarization process is at work which may further induce changes in the rural Thai rubber economy.