To clarify the physicochemical properties, ultrastructure, stability of alginate hydrogel (AH) crosslinked by Zn2+ and assess the biocompatibility of AH 3D scaffold with spinal cord neural stem/progenitor cells (NSPCs). Methods: AH 3D scaffolds were fabricated by crosslinking of alginate with Zn2+ . Then the scaffolds were viewed under the optical microscope and scanning electron microscope to view general and ultrastructure respectively. Optical spectrum analyzer was used to test the concentration of Zn2+ remained in the scaffold after being washed by HCl solution. After incubation in phosphate buffer saline for 18 weeks, the AH scaffolds were weighed and checked under the optical microscope for capillary structure. MTT method was used to quantify the survival rate of NSPCs co-cultured with AH for different days. The differentiation of NSPCs on AH 3D scaffolds was determined by immunofluorescence. Results: The capillary diameter of AH 3D scaffolds was (93.26±6.24) μm, while the porosity of capillaries was (7.83±1.58)% and the density was (68.41±6.51)/mm2 . The concentration of Zn2+ within the scaffold was 0.08 nmoL/mg after 8-time washing by hydrochloric acid. The spinal cord NSPCs could survive (＞90%) well and differentiate into neurons, astrocytes and oligodendrocytes on the AH 3D scaffolds. Conclusion: AH 3D scaffolds have a stable topological structure with few Zn2 + left and show great biocompatibility with spinal cord NSPCs.