  Gravitational waves (GWs) from tens of millions of compact binaries in our
Milky Way enter the milli-Hertz band of space-based detection. The majority of
them cannot be resolved individually, resulting in a foreground confusion noise
for Laser Interferometer Space Antenna (LISA). The concept of Taiji mission is
similar to LISA's with slightly better sensitivity, which means that the
galactic GW signals will also affect the detection with Taiji. Here we generate
the GW signals from 29.8 million galactic binaries for Taiji and subtract the
`resolvable' sources. The confusion noise is estimated and fitted in an
analytic form with 6-month, 1-year, 2-year and 4-year observation time. We find
that the full sensitivity curve is slightly lower for Taiji than for LISA at
frequencies of $\leq 0.8$ mHz and around 2~mHz. For a 4-year lifetime, more
than 29 thousand sources are resolvable with Taiji. Compared to LISA, Taiji can
subtract $\sim 20 \%$ more sources and the distribution of them in our Milky
Way is consistent with that of the resolvable sources with LISA. At frequencies
around 2~mHz or with the chirp masses ranging from $0.2 M_\odot$ to $0.4
M_\odot$, more sources become resolvable with Taiji.
