Abstract: The main agronomic characters of 4 maize inbred lines，which were carried by ‘Shenzhou IV’ spaceship were studied. The results showed that space condition had different effects on seedling emergence, survived and eared plants, the growth rate of plant height and the emergence rate of leaves in various stage, and almost all agronomic characters of various inbreds. All characters varied toward two directions, and their variation range and variation coefficient were all great. The correlations among all characters changed with no regularity.