  In this paper, we mainly use the Galerkin approximation method and the
iteration inequalities of the $L$-Maslov type index theory to study the
properties of brake subharmonic solutions for the first order non-autonomous
Hamiltonian systems. We prove that when the positive integers $j$ and $k$
satisfies the certain conditions, there exists a $jT$-periodic nonconstant
brake solution $z_{j}$ such that $z_{j}$ and $z_{kj}$ are distinct.
