Algebraic immunity has been considered as one of significant properties for Boolean functions. Two constructions of rotation symmetric Boolean functions (RSBFs) in even-variable with maximum algebraic immunity(MAI) were proposed. Furthermore, the nonlinearity of constructed RSBFs were investigated under special cases of Construction 2. When n≥18, the constructed MAI RSBFs by using Construction 3 have higher nonlinearity than that of all known MAI RSBFs in even-variable.