We have observed CRL 2688 (the Egg nebula) in the 13CO J = 1–0 and CS J = 1–0 and 2–1 lines by the Nobeyama Millimeter Array with a resolution of about 4″. The 13CO velocity channel maps show that emission consists of three components; a spherical core, an extended envelope, and a bipolar high-velocity component (Yamamura et al. 1995).A spherical shape of the core despite of the maximum optical depth of about the unity indicates that the disk-like structure, expected from the shape of the bipolar nebula, is smaller than the present beam size (corresponding to about 6 × 1016cm at 1kpc). The combined maps made from the data by the NMA and the Nobeyama 45-m telescope show that emission spreads towards the south of the center more then the opposite direction.