This is the readme for the Simulation Scripts for Chen W and De Schutter E (2017) Parallel STEPS: Large Scale Stochastic Spatial Reaction-Diffusion Simulation with High Performance Computers. Front. Neuroinform. 11:13. doi: 10.3389/fninf.2017.00013 contact: w.chen at oist.jp Scripts in simple_model directory can be used to reproduce data for section Reaction-Diffusion Simulation with Simple Model and Geometry. Scripts in purkinje_model directory can be used to reproduce data for section Large Scale Reaction-Diffusion Simulation with Real-World Model and Geometry. These scripts require the installation of STEPS 3.0.0 with MPI support, STEPS can be downloaded from steps.sourceforge.net.