An extensive photometric monitoring of KH 15D , an enigmatic variable in the young star cluster NGC 2264 , has been conducted .
Simultaneous and accurate near-infrared ( JHKs -bands ) photometry is presented between 2003 December and 2005 March covering most of the variable phase .
The infrared variability is characterized by large-amplitude and long-lasting eclipse , as observed at optical .
The period of variability is 48.3 \pm 0.2 days , the maximum photometric amplitude of variability is \sim 4.2 mag , and the eclipse duration is \sim 0.5 in phase units .
These are consistent with the most recent period , amplitude , and duration at optical .
The blueing of the J-H color ( \sim 0.16 mag ) during the eclipse , which has been suggested before , is unambiguously confirmed ; a similar blueing at H-Ks is less clear but is probably present at a similar level .
The overall shape of the JHKs light curves is very similar to the optical one , including a fair time-symmetry and a less stable flux during the eclipse with a slight hump near the zero phase .
Most of these variability features of KH 15D observed at near-infrared wavelengths can be explained with the recent model employing an eclipse by the inclined , precessing disk and an outer scattering region around a pre-main-sequence binary .