  Using the high tempo-spatial resolution H$\alpha$ images observed with the
New Vacuum Solar Telescope, we report the solid observational evidence of
magnetic reconnection between two sets of small-scale anti-parallel loops with
an X-shaped topology. The reconnection process contains two steps: a slow step
with the duration of more than several tens of minutes, and a rapid step
lasting for only about three minutes. During the slow reconnection, two sets of
anti-parallel loops reconnect gradually, and new loops are formed and stacked
together. During the rapid reconnection, the anti-parallel loops approach each
other quickly, and then the rapid reconnection takes place, resulting in the
disappearance of former loops. In the meantime, new loops are formed and
separate. The region between the approaching loops is brightened, and the
thickness and length of this region are determined to be about 420 km and 1.4
Mm, respectively. During the rapid reconnection process, obvious brightenings
at the reconnection site and apparent material ejections outward along
reconnected loops are observed. These observed signatures are consistent with
predictions by reconnection models. We suggest that the successive slow
reconnection changes the conditions around the reconnection site and triggers
instabilities, thus leading to the rapid approach of the anti-parallel loops
and resulting in the rapid reconnection.
