Kinetic studies were carried out on the reaction between dimeric fatty acid C36 with 1.3 Diamino propane and 1.4 Diamino butane and 1.6 Diamino hexane and 1.8 Diamino octane in molten phase. The reaction was performed at 145ºC. The polyamidation reaction was found to be on the overall a second order up to 83% conversion for reaction dimeric fatty acid C36 with 1.3 Diamino propane and 86% conversion for reaction dimeric fatty acid C36 with 1.4 Diamino butane and 87% conversion for reaction dimeric fatty acid C36 with 1.6 Diamino hexane and 1.8 Diamino octane then the reaction order changes to the third order above last conversion. The degree of polymerization,number average molecular weight and weight average molecular weight have been calculated during different times. Their relationships with the times are linear until last conversion. The melting point and thermodynamic constants for melting are determined by use of differential scanning calorimetry DSC. The melting point and thermodynamic constants increase by increasing the length of reacted amine series.