  This paper analytically investigates a series of two-dimensional MHD
reconnection solutions over a wide variation of magnetic Reynolds number
($R_{em}^*$). A new series of solutions explains a continuous transition from
Petschek-like fast regime to a Sweet-Parker-like slow regime. The inflow region
is obtained from a Grad-Shafranov analysis used by Nitta et al. 2002 and the
outflow region from a shock-tube approximation used by Nitta 2004, 2006. A
single X-point (Petschek-like) solution forms for a sufficiently small
$R_{em}^*$. As $R_{em}^*$ gradually increases, the solutions shifts to an X-O-X
solution with a magnetic island between two X-points. When $R_{em}^*$ increases
further, the island collapses to a new elongated current sheet with Y-points at
both ends (Sweet-Parker-like). These reconnection structures expand
self-similarly as time proceeds. As $R_{em}^*$ increases, the reconnection rate
and the reducible fraction of the initial magnetic energy of the system
decrease as power-law functions of $R_{em}^*$.
