A method of producing polyamide by the direct polycondensation of a diamine component and a dicarboxylic acid component without using a solvent, such as water. The diamine component containing 70 mol % or more of p-xylylenediamine is added to a reaction system containing the dicarboxylic acid component under pressure while maintaining the reaction system in a molten state. After the addition of the diamine component, the pressure of the reaction system is reduced to atmospheric pressure over 50 min or more at a pressure falling speed of 1.0 MPa/h or less. By the production method, polyamide with a small molecular weight dispersion is easily produced.