Abstract: The paper discussed kinematical characteristic of clamping tree mechanismon supporting arm seed collecting ladder and the mathematics models of thebest optimum design were founded for satifying its structure, function andtechnology, and computer program of SUMT+Powell successfuly were run inPC-1500 pocketcomputer. We have optimum designed its series of IZT-SJ.The design not only saved time but also markedly raised technology and precision on it.

Key words: Seed collecting ladder, Clamping tree mechanism, Oputimum design