Abstract In this dissertation, we study some quasi-fixed polynomial problem. It includes five chapters in this dissertation. Chapter 1 : Introduction of this dissertation. Chapter 2 : We focus a real-valued polynomial function F : Rn R ! R and consider the number of all quasi-fixed (polynomial) solutions. We prove the necessary and sufficient conditions when the number of all quasi-fixed polyno- mial solutions is infinitely many and find the upper bound of the number of all solutions when the number is finitely many. Chapter 3 : We prove that the upper bound s + 2 in chapter 2 is necessary. Moreover, we find the necessary or sufficient conditions when the number of all solutions is s + 2 and s + 1. Chapter 4 : We focus a vector-valued polynomial function F : Rn R ! Rk and consider the number of all quasi-fixed (polynomial) solutions. We prove the necessary and sufficient conditions when the number of all quasi-fixed (poly- nomial) solutions is infinitely many and we also find the upper bound of the number of all solutions when the number is finitely many. Chapter 5 : If the number of all quasi-fixed polynomial solutions in Chapter 2 is finitely many. We provide an efficient algorithm to solve all quasi-fixed polynomial solutions.