We studied a peculiar molecular outflow in
L1157 (<A HREF="./paper/l1157.ps"> 	 Zhang et al. 1995</A>).
Powered by a very low mass protostar of only 11 Lsun, the outflow
has significantly changed the chemistry in the ambient environment.
The prominent shocks at the end of the outflow lobes produce strong
line emission in NH3, SiO, CS, and H2. There is an elongated
molecular condensation perpendicular to the outflow axis. This
condensation is likely the flattened core harboring
an unresolved accretion disk.
This outflow represents a
unique type that is powered by extremely young protostars.