Öz This study was carried to investigate the formation and inhibition of microtubules in ultrastructural level by analysing ali the stages of celi division in the control and colchicine treated celIs of root tip meristematic ccIis of Glycine max (L.) Merr. (Soybean). In control cells, circular sections of microtubules were observed near the celi walls in interphase. At the end of the metaphase, it was observed that the nuclear envelope at the poles ruptured and microtubules entered the karyoplasm from there. The number of microtubules reached its marimum level during metaphase. Three different types of microtubules were distinguis- hed namely kinetochoral, free and continuous microtubules. The number of microrubules were observed to decrease starting from the anaphase. There observed some phragmoplast microtubules in the telophase. The maximum effect of colchicine was observed at metaphase and there was no microtubules found in those root tip cells treated with colchicine. It was also determined that the chromosomes could not seperate from each other and stayed cons- tantly at metaphase.