  Presented are the results of a near-IR photometric survey on 1678 stars in
the direction of the \rho Ophiuchus (\rho Oph) star forming region using data
from the 2MASS Calibration Database. For each target in this sample, up to 1584
individual J, H and K_s band photometric measurements with a cadence of ~1 day
are obtained over 3 observing seasons spanning ~2.5 years; it is the most
intensive survey of stars in this region to date. This survey identifies 101
variable stars with \Delta K_s band amplitudes from 0.044 to 2.31 mag and
\Delta(J-K_s) color amplitudes ranging from 0.053 to 1.47 mag. Of the 72 young
\rho Oph star cluster members included in this survey, 79% are variable; in
addition, 22 variable stars are identified as candidate members. Based on the
temporal behavior of the K_s time-series, the variability is distinguished as
either periodic, long time-scale or irregular. This temporal behavior coupled
with the behavior of stellar colors is used to assign a dominant variability
mechanism. A new period-searching algorithm finds periodic signals in 32
variable stars with periods between 0.49 to 92 days.
