n this talk we will characterize the irreducible quasifinite highest weight modules of some subalgebras of the lie algebra of matrix quantum pseudodifferential operators $n \times n$. in order to do this, we will first give a complete description of the anti-involutions that preserve the principal gradation of the algebra of $n\times n$ matrix quantum pseudodifferential operators and we will describe the lie subalgebras of its minus fixed points. we will obtain, up to conjugation, two families of anti-involutions that show quite different results when $n=n$ and $n< n$. we will then focus on the study of the ``orthogonal'' and ``symplectic'' type subalgebras found for case $n=n$, specifically the classification and realization of the quasifinite highest weight modules.