PURPOSE: To provide the synthetic peptide intermediate compositions each of which is formed in a solid phase or solution process of the synthesis of a peptide having releasing activity of pituitary growth hormone and is bound to a resin, protecting group or the like, and is used as an intermediate for the preparation of a therapeutic agent for dwarfism or the like.

CONSTITUTION: When performed the synthesis of a peptide having releasing activity of pituitary growth hormone, in the solid phase process, such an intermediate composition represented by formula I or II is formed by repeating an operation that comprises binding amino acids whose amino groups are protected, to a solid phase supporter such as p-methylbenzhydrylamine resin and thereafter, removing the amino-protecting groups, wherein in formula I: R is a resin; each of X1"' to X3"' is an N-terminal group or the like; each of B1 and B4 is His or the like; each of B2, B5 and B6' is D-His or the like; B3 is Gly or the like; Pr1 is an amino- protecting group; and each of (a), (b), (q), (r) and (s) is 0 or 1, and in the formula II: B6 is an L-amino acid group; and each of X1IV to X3IV is the same species as X1"'. On the other hand, in the solution process, such an intermediate composition represented by formula III (Y is a C-terminal group or the like; and B5' is the same species as B5), IV (Pr2 is a carboxyl protecting group), V, VI (B6' in the same species as B6), VII or VIII, is formed by protecting C-terminal groups of amino acids and then, successively binding the amino acids.