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Induction of polyploidy by experimental methods has been proved to be a handy tool in tampering with the genotype of the organisms and in widening the amplitude of variation in the gene pool. Though various methods of induction of polyploidy have been developed, induction through the application of colchicine has been met with remarkable success especially with many herbaceous plants.As a part of the programme of induction of polyploidy in various species of Amaranthaceae two species viz. Amaranthus hypochondriacus L. and Amaranthus dubius Mart. ex Thell. were induced for polyploidy. As the vegetative parts such as the leaf and stem of various species of Amaranthus L. are edible and autopolyploidy very often magnifies the vegetative characters, this programme of work has been undertaken to evaluate whether such an effort will be of economic value and whether some improved varieties of this crop can be raised.Attempts to induce polyploidy in some species of Amaranthus L. had been made in the past. Murray (1940) induced tetraploidy in some monoecious and dioecious species of Amaranthus L. Tandon and Chinoy (1950) also made effort to induce te traploidy in A. blitum L. Recently Pal and Khoshoo (1968) induced tetraploidy in A. edulis Speg. and have made detail analysis of the tetraploids through C0 and C1 generations.About 10 species of Amaranthus L. grow throughout India, almost all of which are edible. The reports of the induction of polyploidy in this genus seem to be fragmentary. With a view to have wide scale induction of polyploidy in this genus the present work is undertaken. Materials and methodsThe seeds of Amaranthus hypochondriacus were obtained from the state Agricul ture Department and those of A. dubius were procured from the local gardens.Two different types of colchicine treatments were adopted i.e. i) seed treat ment and ii) seedling treatment. The different concentrations of colchicine used in both the treatments were 0.1, 0.2, 0.3, 0.4 percent of aqueous solution.i) Seed treatment: The seeds were soaked in aqueous solutions of colchicine of different concentrations in petridishes for six hours. A set was maintained as control by soaking the seeds in distilled water. After soaking, the seeds were thoroughly washed in tap water and were sown in flat earthenware pots as well as in the field. The results of such treatment were not promising because very few seeds germinated.