A summary of some recent results of neutron scattering studies of high temp
erature superconductors is given, with a focus on resonant spin excitations
in the superconducting states of YBa2CU3O6+x and Bi2Sr2CaCu2O8+delta. The
opportunities offered by advances in neutron scattering instrumentation, su
ch as focusing and polarization techniques, for these experiments are discu
ssed, (C) 1999 Published by Elsevier Science Ltd. All rights reserved.