Extending on the work of Kudla-Millson and Yuan-Zhang-Zhang, together with Yott we are constructing special divisors for a specific GSpin Shimura variety. We further construct a generating series that has as coefficients the cohomology classes corresponding to the special divisors classes Z(x, g)_K on the GSpin Shimura variety M_K and show the modularity of the generating series in the cohomology group over C.