  We discuss the role of protostellar outflow feedback in clustered star
formation using the observational data of recent molecular outflow surveys
toward nearby cluster-forming clumps. We found that for almost all clumps, the
outflow momentum injection rate is significantly larger than the turbulence
dissipation rate. Therefore, the outflow feedback is likely to maintain
supersonic turbulence in the clumps. For less massive clumps such as B59,
L1551, and L1641N, the outflow kinetic energy is comparable to the clump
gravitational energy. In such clumps, the outflow feedback probably affects
significantly the clump dynamics. On the other hand, for clumps with masses
larger than about 200 M$_\odot$, the outflow kinetic energy is significantly
smaller than the clump gravitational energy. Since the majority of stars form
in such clumps, we conclude that outflow feedback cannot destroy the whole
parent clump. These characteristics of the outflow feedback support the
scenario of slow star formation.
