We report measurements of the magnetization and diamagnetic susceptibility of a polycrystal of LaBaCaCu3O7-δ. The sample has a zero-field transition temperature Tc0 = 77 K and a transition width of 2.0 K. The results show large fluctuation effects, which can be explained by Ginzburg-Landau fluctuation theory for a two-dimensional (2D) system. The experimental data for the magnetization in high magnetic fields (20-50 kOe), were fitted by using a theoretical model based on the lowest-Landau-levels approximation, showing good agreement. The weak-field fluctuation diamagnetic susceptibility above Tc can be fitted well in terms of the 2D Lawrence-Doniach model.