Abstract: The anticonvulsant activities of thirty-eight cinnamamides have been used to formulate quantitative structure-activity relationships. The correlations indicate that the activity of these series of compounds is parabolically related to the partition coefficients (log P octanol/water) of the compounds. Hammett σ constants and steric parameter (MR) of the substituents can significantly improve the correlations. The equation indicates that the substituents with electron Withdrawing effect and small steric parameter will increase anticonvulsant activity of cinnamamide. The correlation analysis of twenty N-cinnamoyl piperidines out of the thirty-eight cinnamamides gives a similar equation.