Several techniques together with some partial answers are given to the questions of factoriality, type classification and fullness for amalgamated free product von Neumann algebras.This fact is easily confirmed in the exactly same way as in [27, Lemma 2.1]. It is clear that E • E M k = E holds. Consider the natural inclusion of the so-called continuous cores:which is independent of the choice of χ thanks to Connes's Radon-Nikodym cocycle theorem. The canonical liftings (still being faithful normal conditional expectations) E :4) Remark that the original E and E k are recovered as the restrictions of E and E k to M and M k via the canonical embeddings M ֒→ M and M k ֒→ M k , respectively. Here is a simple but important fact [21, Theorem 5.1] that M 1 and M 2 are freely independent with amalgamation over N with respect to E, and moreover M = M 1 ∨ M 2 . Consequently the following natural formula holds: ( M , E) = ( M 1 , E 1 ) ⋆ N ( M 2 , E 2 ). (2.5) The canonical faithful normal semifinite traces Tr M , Tr M k (k = 1, 2) and Tr N on M , M k and N , respectively, (see [20, Theorem XII.1.1]) must satisfy Tr M = Tr N • E and Tr M k = Tr N • E k (see e.g. [14, §4]).