Abstract:This paper uses regression analysis to investigate the relationship between technological innovation and the cost of equity capital. Empirical studies find that: (i) the cost of equity capital of enterprise shows different trends over time in different stage of the life cycle: a downward trend in the growth stage, an upward trend in maturity stage and decline in rendering stage; (ii) there is a "U" shaped relationship presenting between technological innovation and the cost of equity capital, because of technological innovation can reduce the information asymmetry at initial investment levels, reduce the expected rate of return, then can reduce the cost of equity capital, but when technological innovation bring technological innovation output which will lead to the increase of the cost of equity capital; (iii) because enterprises in different life cycle stage will have different financial and organizational characteristics, technological innovation has a negative impact on the cost of equity capital in growth and maturity stage, while have a positive impact in recession stage.