SUPPLEMENT DATED OCTOBER 26, 1998, TO
                        THE PROSPECTUS DATED MAY 1, 1998
                      FIRSTLINE II VARIABLE UNIVERSAL LIFE
               A FLEXIBLE PREMIUM VARIABLE LIFE INSURANCE POLICY
                                   ISSUED BY
                   SECURITY LIFE OF DENVER INSURANCE COMPANY
                                      AND
                       SECURITY LIFE SEPARATE ACCOUNT L1

THIS SUPPLEMENT UPDATES CERTAIN INFORMATION CONTAINED IN YOUR PROSPECTUS. PLEASE
READ IT CAREFULLY AND KEEP IT WITH YOUR PROSPECTUS FOR FUTURE REFERENCE.

The first sentence in the "Policy Loans" section on page 27 is changed to read:

     "At any time after the first policy Monthly Processing Date, or as
     otherwise required by law, the Owner may borrow against the Policy by using
     it as security for a loan."

Effective July 6, 1998, INVESCO Funds Group, Inc. ("IFG"), the investment
adviser to INVESCO Variable Investment Funds, Inc., changed the arrangements by
which it voluntarily absorbs certain expenses of the INVESCO VIF - High Yield
Portfolio, INVESCO VIF - Industrial Income Portfolio, INVESCO VIF - Small
Company Growth Fund, INVESCO VIF Total Return Portfolio, and INVESCO VIF -
Utilities Portfolio. See Pages 35 - 37 of the prospectus. The annual expenses of
these Portfolios, restated to reflect these changes, are as follows:



       PORTFOLIO          INVESTMENT    OTHER EXPENSES     TOTAL
                          MANAGEMENT                     PORTFOLIO
                             FEE                         EXPENSES
===================================================================
                                                
INVESCO VIF - High           0.60%           0.45%          1.05%
 Yield Portfolio                                          
                                                          
INVESCO VIF -                0.75%           0.40%          1.15%
 Industrial Income                                        
 Portfolio

INVESCO VIF - Small          0.75%           0.50%          1.25%
 Company Growth Fund
                                                          
INVESCO VIF - Total          0.75%           0.40%          1.15%
 Return Portfolio                                         
                                                          
INVESCO VIF -                0.60%           0.55%          1.15%
 Utilities Portfolio



                                     * * *

The illustrations of death benefits, account values and surrender values, and
accumulated premiums included on pages 47 - 54 of the prospectus reflect, among
other policy fees, charges, and costs, the simple average of total Portfolio 
expenses for all Portfolios available through the Policy. Taking into account 
the changes affecting the INVESCO VIF Portfolios described above, this simple 
average increases from .07907% to .8387%.

 
The third paragraph in the "Distribution of the Policies" section on pages 45 -
46 is deleted and replaced in its entirety as follows:

     "Under these selling agreements, we pay a distribution allowance to the
     other broker-dealers, which in turn pay commissions to the Registered
     Representative who sells this Policy.  The distribution allowance may equal
     an amount up to 95% of the first Target Premium paid.  For premiums paid in
     excess of the first Target Premium, the distribution allowance may equal an
     amount up to 4% in policy years one through ten, and 2% in subsequent
     years.  Broker-dealers may also receive annual renewal compensation of up
     to 0.15% of the Net Account Value beginning in the eleventh Policy year.
     Compensation arrangements may vary among broker-dealers and depend on
     particular circumstances.  In addition, we also may pay override payments,
     expense allowances, bonuses, special marketing fees, wholesaler fees, and
     training allowances.  Registered Representatives who meet specified
     production levels may qualify, under our sales incentive  programs, to
     receive  non-cash  compensation  such as  expense-paid  trips,  expense-
     paid educational  seminars and merchandise."


The third and fourth sentences of the first paragraph in the "Partial 
Withdrawals" section on page 28 are deleted and replaced in their entirety as 
follows:

     "We may impose requirements on Partial Withdrawals as necessitated by our
     administrative system. For example, we may require that requests be a
     specified dollar amount rather than a percentage."