PURPOSE: To obtain the title polyamide having excellent spinnability with excel lent productivity, by connectedly polymerizing specific polyhexamethylene adipamide having a low polymerization degree with adipic acid dichloride in a solvent.

CONSTITUTION: Polyhexamethylene adipamide having a low polymerization degree of 2W200 and ≤40 mequiv./103g number of carboxyl terminal groups is connectedly polymerized with adipic acid dichloride in a solvent (e.g. N- methyl-2-pyrrolidone) to afford the aimed polyamide having >20, preferably 200W600 polymerization degree. Furthermore, a dissolution assistant, such as lithium chloride, calcium chloride or magnesium chloride, is preferably used.