  Let $m$ and $n$ be two positive integers such that $m < n$. Let $Q_{n-m+1}$
be the symplectic quasi-projective space of rank $n-m+1$. In this article, we
will study the order of the Samelson product $S^{4m-1}\wedge
Q_{n-m+1}\rightarrow Sp(n)$.
