Much land in the Shawnee Hills of Southern Illinois, originally covered by oak—hickory forests, was cleared for cultivation by the mid 1800's and later abandoned because of severe erosion and low crop production. Plant succession was studied on such abandoned fields of eight different ages ranging from 1 year to 40 years old. First—year fields were occupied principally by annuals. Perennial herbs were prominent in the following few years. Shrubs and trees formed the bulk of vegetation on 40—year fields or more. Seed germination of some of the early invaders was also investigated. The general trend in succession is discussed.