This study aims to describe the validity of worksheet on the concept of Environmental Change using the solution to the developed wetland problem. Problem-solving models are learning models that can be used related to answers to wetland environmental problems on the concept of environmental change. The validity of the worksheet is viewed from the six aspects, namely the material, linguistic, presentation, format, bibliography and particular elements of the model for solving wetland problems. The worksheet was validated by two validators, consisted of biology education lecturers. It was found that the validity of the spreadsheet an average for all aspects of 91.6% which is categorized as a very feasible category. Based on the results, it can be concluded that the spreadsheet of environmental change concept using a model for resolving the developed wetland problem is valid. Keywords—validity; worksheet; problem-solving; wetlands