Abstract: This treatise, on the basis of Rife-Buranamanas's law about frequencies of trait combinations between females and their children, discriminated genetic machinism of 8 kinds of Mendelian characters in Tupaia belanger, by means of population genetics and probability matrix probed into the efficiency of 4 different breeding systems (animal coloing, superovulation & embryo transfer, “breeding of habrid animals with desirable phenotype in themselves” and multiple testcross) in maintaining general genetic diversity while purifying the Mendelian characters in domesticating colony of Tupaia belangeri. It was confirmed that, in setting of genome of Tupaia belangeri, the coating color of wild type, black orbit, white fur of abdomen, seasonal spot, flesh color of palm, flat ear, round tail and symmetry breast are dominant Mendelain characteristics; as far as the breed with definite scale is concerned, the ratio between percentages of the cull of next generations under different systems is also the ratio between inbreeding increments under these systems and losses of gene heterozygosity under these systems. If n stands for the number of breeding characteristics based on dominant gene and t the number of generations selected, then probabilities of homozygosized individuals at all (as many as n) the loci in the tree shrew populations under the two sestems of “breeding of hybrid animals with desirable phenotype in themselves” and multiple testcross are in such a sequence: , In regard to purification, the latter is higher in efficiency than the former. Taking the wild type and 3 mutation types of Drosophila melanogaster as subject, simulated the selection and breeding meant to purify population of the tree shrew and the results conformed to theoretic investigation.

Key words: Tupaia belangeri, Mendelian characterestic, purifacation