  In our recent paper entitled "Quantum Quasi-Cyclic Low-Density Parity-Check
codes" [ICIC 2009. LNCS 5754], it was claimed that some new quantum codes can
be constructed via the CSS encoding/decoding approach with various lengths and
rates. However, the further investigation shows that the proposed construction
may steal some ideas from the paper entitled "Quantum Quasi-Cyclic LDPC codes"
[quant-ph/0701020v2]. We feel that the apologizing point of the original
protocol is that some results are almost similar to that of construction
methods with algebraic combinatorics although we suggest the different approach
for improving them. Also, there is a weak point of the original coding approach
while considering the application of codes in imperfect channels.
