This paper examines the accentuation pattern of loanword of Japanese. Generally, nativized loanwords neglect its morphological structure from source language. Some types of Japanese loanwords, however, show their accentuation patterns of root+suffix structure although they have already constituted simplex words.BR To solve this problem, I adapt the conception of pseudo-compounding (Sato 2002, Giriko 2010). After investigating the word accents from NTT database series Nihongo-no Goitokusei (Lexical properties of Japanese), the author classified the accentual feature of pseudo-morphemic suffixes ―/-ikku/(-ic), /-izumu/(-ism), /resu/(-less), /-mento/ (-ment). /-aa/ (-er, -or), /-shon/(-tion, -sion) and /-ingu/ (-ing)― as follows.BR pseudo-morphemic feature on accentuationBR [initial accenting] : /-ikku/(-ic), /-izumu/(-ism)BR [recessive] : /resu/(-less), /-mento/ (-ment). /-aa/ (-er, -or)BR [recessive, dominant pre-accenting] : /-shon/ (-tion, -sion)BR [recessive, deaccenting] : /-ingu/ (-ing)BR These classification will shed light on hidden generalization of Japanese accent patterns.