In this paper, we de…ne the associate matrix asBy the means of the matrix F; we give several identities about Fibonacci and Lucas quaternions by matrix methods. Since there are two di¤erent determinant de…nitions of a quaternion square matrix (whose entries are quaternions), we obtain di¤erent Cassini identities for Fibonacci and Lucas quaternions apart from Cassini identities that given in the papers [5] and [7].