Abstract: This paper selects 67 companies which all have sales outside Chinese M ainland in Shenzhen Security Exchange to study the impact of the fluctuation of exchange rate to the return rate of stock price. The result reveals that under 0 .1 levels of significance 7 companies have positive exchange risk exposure coeff icients and 12 companies have negative exchange risk exposure coefficients. Then we analyze the reasons why some coefficients are positive while the others are negative. The study finds that companies with positive coefficients increased th e sales ratio outside China mainland at the cost of reducing gross profits. Fina lly, we analyze the factors affecting the size of the exchange risk exposure coe fficients.