The variational adjoint method in combination with Tikhonov regularization principle is applied to retrieve the initial gas concentrations and reaction rates in chemical reactions about ozone destroying in the stratosphere.The adjoint models and functional gradients are deduced for the complete and incomplete(terminal time)observations of the gases'concentrations,respectively.Finally,a series of ideal numerical experiments are preformed to show the validity of the variational adjoint method.Especially,Tikhonov regularization principle can be used to overcome the ill-posedness in the case of combinational retrieving for incomplete observations.