In this paper, a topological degree for Quasi-A-proper Mappings is established on the basis of theory of topological degree for A-proper Mappings. It shows that both degrees have almost the same properties. Solvability, surjectivity and fixed point theorem of some Quasi-A-proper mappings or equations are studied in the paper. We can see that most mappings of monotone type are Quasi-A-proper mappings. Therefore, some new results in the theory of mappings of monotone type are obtained. |