An experiment scoured 60/1 ramie yarns and 40/1 linen yarns, mercerized the yarns without tension in a 20 percent by weight aqueous solution of sodium hydroxide at 20 degrees centigrade for 20 minutes, washed the yarns in water, and dried them. Hydrolyzing the yarns for 0.5-120 hours in a 5N aqueous solution of hydrochloric acid at 25 degrees centigrade obtained samples with various molecular weights. Results showed no effect of the crystalline region on the tensile properties of the ramie and linen fibers. A decrease in molecular weight decreased the effects of moisture regain on the tensile strength and elongation of the fibers. The slope in the plot of tensile properties versus moisture regain became negative when the molecular weights of ramie and linen fell below approximately 1.22 x 10(5) and 0.99 x 10(5), respectively. The number of molecular chain ends in the amorphous region affected the changes in tensile strength and elongation with moisture regain. 8 refs.