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Marigold (Tagetes erecta L.) which demonstrated the high allelopathic activity in the bioassay was fractionated by simple partitioning procedure which separated the components into gross chemicals classes.An aqueous-ethanol crude extract (OR) of dried marigold leaves was partitioned into ethyl acetate soluble acidic (AE) and neutral (NE) fractions, and aqueous (AQ) fraction.The growth inhibitory activities of AQ, NE, and AE fractions were compared with the original extract (OR).Although, the concentrations for bioassay varied from 2000 to 16,000 ppm, most fractions inhibited germination and seedling growth of wild pea (Phaseolus lathyroides) various degrees.The original extract showed strong activity, giving 88.75%, 100% and 100% inhibition of wild pea germination, shoot length and root length, respectively at the concentration of 16,000 ppm.After solvent partitioning, at this step, relative inhibition increased, as compared to the original extract.The AE fraction showed the greatest activity fraction with complete inhibition of germination, shoot length and root length of P.lathyroides at the concentration of 16,000 ppm.The NE and AQ fractions showed a weaker inhibition effect on P.lathyroides germination shoot length and root length when compared with the OR fraction.These results indicated that most of phytotoxic compounds produced by T.erecta could be presented in AE fraction.