This study applies "Types of Investors" of 323 private placement of common shares and preferred stocks event as samples. Financial firm data covered the years 2004 through 2011 was acquired from the Taiwan Stock Exchange and Taiwan's OTC. One part of this study is to test the effects of "Types of Investors" on the "Private Equity Placement Discounting. The other part is to test the effects of "Annual Report Information Disclosure" and "Annual Report Information DisclosureCombination" on "Discount Rate of Private Equity PlacementDiscounting". The results of this study: "External Investors" and"Mandatory InformationDisclosure" significantly negative affect on "Discount Rate of Private Equity Placement Discounting". The moderating effects show that "Internal Investors" enhance the negative relationship between "Mandatory Information Disclosure and Private Equity Discounting". "Outside Investors" weaken the negative relationships between "Annual Report Information Disclosure and Private Equity Dis counting" and "Mandatory Information Disclosure and Private Equity Discounting".