  We prove several versions of reverse triangle inequality in Hilbert
$C^*$-modules. We show that if $e_1, ..., e_m$ are vectors in a Hilbert module
${\mathfrak X}$ over a $C^*$-algebra ${\mathfrak A}$ with unit 1 such that
$<e_i,e_j>=0 (1\leq i\neq j \leq m)$ and $\|e_i\|=1 (1\leq i\leq m)$, and also
$r_k,\rho_k\in\Bbb{R} (1\leq k\leq m)$ and $x_1, ..., x_n\in {\mathfrak X}$
satisfy $$0\leq r_k^2 \|x_j\|\leq {Re}< r_ke_k,x_j> ,\quad0\leq \rho_k^2
\|x_j\| \leq {Im}< \rho_ke_k,x_j> ,$$ then
[\sum_{k=1}^m(r_k^2+\rho_k^2)]^{{1/2}}\sum_{j=1}^n
\|x_j\|\leq\|\sum_{j=1}^nx_j\|, and the equality holds if and only if
\sum_{j=1}^n x_j=\sum_{j=1}^n\|x_j\|\sum_{k=1}^m(r_k+i\rho_k)e_k .
