Abstract: ObjectiveTo investigate the changes of the morphology, growth and cycle of CHO(dhfr^-) cells after space flight.MethodsCHO(dhfr^-) cells were carried in the No.18 recoverable satellite and monocloned harvesting cells before multiplying. 4 cell lines were selected randomly,and the growth characteristics of the most slowly growing one at the fifth passage was observed by methods of MTT and FCM as well as the cells' shape.Results159 cell strains were obtained after monocloning and multiplying. The cells' morphology changes, growth speed decrease and the number of G1 phase increased markedly.ConclusionSpace flight induced morphological changes of cells and it is impossible to screen out finer bioengineering cells.

Key words: CHO(dhfr^-) cell, outer space, growth characteristic