〔Abstract〕 Objective To research the feasibility of Laponite®(LAP)-sodium alginate(SA) guided bone regeneration composite film used as tissue engineering barrier films by testing its mechanical properties and biocompatibility.Methods Pure SA solution and binary mixture with different LAP and SA ratios(1 ∶10, 3 ∶10, 5 ∶10, 7 ∶10, 9 ∶10) were formed into films through thermal spraying. The tensile strength of the composite films were tested by mechanical universal testing machine(n=6). The microstructure of pure SA film and the composite film with the best tensile strength was observed by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). X-ray diffraction(XRD) and Fourier transform infrared(FTIR) spectrometer were used to characterize the ingredients of the material. Samples with the highest tensile strength was prepared again, followed by immersing in 0.5 mol/L calcium chloride solution for 5 s. The tensile strength of the new group of samples was tested after natural drying. Cell counting kit-8(CCK-8) was applied to detect cell counts in the blank control group, the pure SA film group, the composite film group with the highest tensile strength(n=5) and all groups co-cultured with the NIH/3 T3 for 24 h and 48 h.Results After adding LAP, the cross-section of the composite film showed ordered layer structure. XRD and FTIR showed that LAP could be found in the composite film. The tensile strength first increased and then decreased with the increase of LAP proportion in composite films. The optimal mass ratio of LAP and sodium alginate in composite film was(5 ∶10), and the tensile strength reached(166.9±11.5) MPa before and(178.0±14.8) MPa after Ca2+chelation. The CCK-8 test of NIH/3 T3 showed that there was no significant difference in absorbance between the pure SA film group and the LAP-SA composite film group when they were compared with the blank control group. Conclusion When the mass ratio of the composite film is 5 ∶10, the composite film has the best tensile strengthand good cytocompatibility.