  This paper is the first part of the Catalog of Periodic Variable Stars in the
Galactic bulge. The Catalog is based on observations collected during the OGLE
microlensing search. 213 periodic variable stars brighter than I=18 mag: 31
pulsating, 116 eclipsing and 66 miscellaneous type variables from the Baade's
Window BWC field are presented. Periodic variable stars from remaining 20
fields will be presented in similar form in the next parts of the Catalog. The
Catalog as well as observations of all periodic variable objects are available
to astronomical community over the Internet network.
