A free energy functional of nonlocal type is considered that was origi
nally introduced to describe the micro-phase separation of diblock cop
olymer. A mathematical framework is given to the issues of the scaling
law for stationary states and the governing equation of morphology. T
he scaling law is equivalent to finding a nice rescaling in order to h
ave a well-defined limiting interfacial problem which is free from the
interfacial thickness and the total chain length of copolymer, and th
e associated stationary problem becomes a morphology equation that gov
erns the configuration of final patterns. Although the steady patterns
become finer and finer in our scaling limit due to the mesoscopic nat
ure, a possible rigorous approach is presented to stability and morpho
logical selection problems for them.