Research on biopolymer formulation and scaffold fabrication has been intense over the past 10 years. The ideal scaffold should have microstructure tailored to facilitate cellular attachment, proliferation and differentiation, adequate mechanical strength and an appropriate biodegradation rate. It is known that crystallization can occur during polymer cooling and also during the degradation of PLA yarns under aging conditions. Chain scission in the amorphous phase may release previously entangled chain segments that become sufficiently free to find a spatial rearrangement into the crystalline phase. But it was considered that chemicrystallization during aging don’t improve mechanical properties because developed crystallites are not perfect. The aim of this research was to find the relationship between biodegradation rate and crystalline structure of PLA yarns produced under different technological conditions.