Abstract: In order to obtain high quality of Poly(lactic acid)(PLA)/ Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)（PLA/PHBV） two-component biodegradable spun-bonded nonwovens, the relative molecular weight and distribution, melt flowing index, thermal properties, crystallization and rheological behavior of PLA/PHBV masterbatch were investigated, the thermal properties and crystallization of spun-bonded fiber were also discussed. The results showed that the weight-average molecular weight of PLA/PHBV was about 120000 and molecular weight distribution was 1.99；The initial decomposition temperature was 285 ℃，it was suitable for spun-bonded extrusion processing and the appropriate processing temperature was about 210 ℃. The apparent viscosity of PLA/PHBV melt was sensitive to the shear rate when under 1000 rad/s，but the level of sensitivity to temperature lowered when the shear rate increased. The spun-bonded processing conditions had significant effects on the thermal properties and crystallization of PLA/PHBV masterbatch，compared with masterbatch，the degree of crystallinity of spun-bonded fiber decreased obviously but the orientation in amorphous region increased.