  Persistent outflows have recently been detected at boundaries of some active
regions. Although these outflows are suggested to be possible sources of the
slow solar wind, the nature of these outflows is poorly understood. Through an
analysis of an image sequence obtained by the X-Ray Telescope onboard the
Hinode spacecraft, we found that quasi-period outflows are present in the
boundary of an active region. The flows are observed to occur intermittently,
often with a period of 5-10 minutes. The projected flow speed can reach more
than 200 km/s, while its distribution peaks around 50 km/s. This sporadic
high-speed outflow may play an important role in the mass loading process of
the slow solar wind. Our results may imply that the outflow of the slow solar
wind in the boundary of the active region is intermittent and quasi-periodic in
nature.
