Dreaming of a box means your instinctual nature and destructive impulses.  Alternatively, you may be trying to preserve and protect some aspect of yourself. The box may also symbolize your limitations and restrictions.  Dreaming that you are opening a box indicates that things are being revealed about yourself that were once hidden. Consider your feelings as you open the box. If opening the box fills you will fear, you may be uncovering aspects of yourself that make you feel anxious. Also consider the pun, "being boxed in".