Generalized self-shrinking sequences are a novel class of stream ciphers.Run-lengths is an important criterion to measure the pseudorandom property of sequences.A good pseudorandom sequence should have short run-lengths.In this paper
by using some pseudorandom properties of m sequences
we obtain a new result about family of the generalized self-shrinking sequences.It is that the run-lengths of each sequence in the sequences family
with the exception of two sequences(000… and 111…)