Abstract:The seeds of Impatiens balsamina L. （Balsaminaceae） were carried by spacecraft Shenzhou 4 on December 30, 2004 which flew for 6 days and 19 hours. The changes in cotyledons were observed in the third generation of the plants. The experiments showed that there were differences in number, size and shape of cotyledons. Four types of cotyledons were found： dicotyledons, tricotyledons, syncotyledons and funnel-shaped cotyledons. The growth period, flowering and fertility were also observed. Whether the variations in cotyledons are caused by physiological or genetic factors must await more research.