The effects of dicumyl peroxide (DCP) at low concentrations on initiating cross-linking of polylactide (PLA) by melt blending were investigated. Processing characteristics, morphology, thermal behavior and rheology character of PLA gel were characterized by torque rheometer, XRD, DSC and rotary rheometer. The results showed that the crosslink rate of the blends increased with dicumyl peroxide content increasing. The PLA gel with 0.73 wt% of DCP appeared obvious crystallization behavior and a new crystalline structure maybe formed as DCP was 1.4 wt%. And it was also found that the exothermal peak temperature of PLA gel decreased with increasing dicumyl peroxide content except for the gel with 1.4 wt% of dicumyl peroxide. It also has been inferred by rheology analysis that the blend may be the structure of gel or 3D network, and the melt strength was improved.