Exhibit 99.1

 Hercules Announces $25 Million Increase in Its Credit Facility with
      Citigroup for a Total of $150 Million of Borrowing Capacity


    PALO ALTO, Calif.--(BUSINESS WIRE)--Dec. 6, 2006--Hercules
Technology Growth Capital, Inc. (NASDAQ:HTGC), a leading specialty
finance company providing debt and equity growth capital to venture
capital and private equity backed technology and life science
companies, has amended its credit facility with Citigroup Global
Markets Realty group, an affiliate of Citigroup, Inc., to increase the
borrowing capacity on its existing credit facility to $150 million
through March 31, 2007. The terms and conditions of the borrowing
increase remain the same.

    About Hercules Technology Growth Capital:

    Founded in December 2003, Hercules Technology Growth Capital, Inc.
is a NASDAQ traded specialty finance company providing debt and equity
growth capital to technology-related companies at all stages of
development. The Company primarily finances privately-held companies
backed by leading venture capital and private equity firms and also
may finance certain publicly-traded companies. Hercules' strategy is
to evaluate and invest in a broad range of ventures active in
technology and life science industries and to offer a full suite of
growth capital products up and down the capital structure to
prospective clients ranging from early-stage growth to expansion stage
companies. The Company's investments are originated through its
principal office located in Silicon Valley, as well as additional
offices in the Boston, Boulder and Chicago areas. Providing capital to
publicly-traded or privately-held companies backed by leading venture
capital and private equity firms involves a high degree of credit risk
and may result in potential losses of capital.

    For more information, please visit www.HerculesTech.com, or
www.HTGC.com. Companies interested in learning more about financing
opportunities should contact info@HTGC.com, or call 650.289.3060.

    Forward-Looking Statements:

    The statements contained in this release that are not purely
historical are forward-looking statements. These forward-looking
statements are not guarantees of future performance and are subject to
uncertainties and other factors that could cause actual results to
differ materially from those expressed in the forward-looking
statements including, without limitation, the risks, uncertainties and
other factors we identify from time to time in our filings with the
Securities and Exchange Commission. Although we believe that the
assumptions on which these forward-looking statements are reasonable,
any of those assumptions could prove to be inaccurate and, as a
result, the forward-looking statements based on those assumptions also
could be incorrect. You should not place undue reliance on these
forward-looking statements. The forward-looking statements contained
in this release are made as of the date hereof, and Hercules assumes
no obligation to update the forward-looking statements for subsequent
events.

    CONTACT: Hercules Technology Growth Capital, Inc.
             Main, 650-289-3060
             info@herculestech.com
             David Lund, 650-289-3077
             dlund@herculestech.com