In this paper, we give a necessary and sufficient condition for the hyponormality of the block Toeplitz operators $T_{Phi}$, where ${Phi}$ = $F+G^*$, F(z), G(z) are some matrix valued polynomials on the vector valued Bergman space $L^2_a(mathbb{D},mathbb{C}^n)$. We also show some necessary conditions for the hyponormality of $T_{F+G^*}$ with $F+G^*{in}h^{infty}{otimes}M_{n{ imes}n}$ on $L^2_a(mathbb{D},mathbb{C}^n)$.