Abstract:The areal-type means distribution map of certain plants always same or nearly same. This is an important method in floristic research to divide distribution into different areal-types. More than 3116 gen-era of seed plants have been recorded in China. They have been classified into 15 areal-types and 37 sub-types . The certain number represent certain areal type such as number 2 always means pantropic distribu-tion pattern. After repeated to tests and uses, it has been proved that characteristics and relationships of each areal type can be showen by such classification. A classification precept of families of seed plants of the world has been proposed at present paper.