To obtain a polyamide resin compsn. improved in melt spinnability, film-forming properties, and processibility by melting a polyamide resin compsn. having a specified water content at a specified temp. under a specified pressure for a specified time to reduce the cyclic monomer content of the compsn. to a specified value or lower.

A resin compsn. contg. a polyamide resin (e.g. a nylon 6 homo or copolymer) and a basic org. compd. in a molar ratio of terminal carboxyl group to the basic compd. of 10 or lower and having a water content of 0.02 wt.% or lower is melted under a pressure of 0.01 Torr or lower at 260°C for 4 hr to reduce the cyclic monomer content to 2.0 wt.% or lower of the resin. The basic org. compd. is a bridged, at least bicyclic compd. having at least one ring-forming nitrogen atom and is a phosphazene compd. of formula I [e.g. 1-butylimino-tris(dimethylamino)phosphorane]. In the formula, R1 is a 1-8C alkyl; X is NR2 (wherein R is 1-5C alkyl or a group of formula II); and l, m, and n are each 0-3.