Law schools require no particular major, and there are no prerequisite courses.  It is recommended that potential applicants include courses that emphasize writing, research, critical thinking, and analytical reading.   In addition, consider courses that develop analysis, argument, and quantitative skills.   Consider taking some upper level courses in liberal arts such as Political Science, Economics, and Sociology. Law schools seek broad diversity among applicants; including diversity of majors. 

Your GPA is by far more important than your major.  Choose a major that you thoroughly enjoy, one in which you can excel and one that will give you an alternate career or graduate study opportunity should you change your mind about law school.