Generally speaking,the investment in auto industry is distributed into many steps,which work on each other.The former step is based on the probability of all the following investment,so we can say the in- vestment in auto industry is a serial-step-investment.This paper establishes an investment valuation model based on serial-step-investment and analysis the solution of this model using real option theory,binomial model and stochastic walk theory.Through this automobile project investment decisi...