Declarative memory, which depends on the medial temporal lobe (MTL) structures, consists of two sub-categories: semantic memory and episodic memory. The former refers to general knowledge of facts, while the latter refers to memories of autobiographical events containing items, times and places. In this talk, I will present neurophysiological data examining the two memories in macaque brains. Semantic memory was tested using an item-item association task in which subjects were required to retrieve a particular visual object when its paired object was presented as a cue stimulus. The single-unit data suggested that bidirectional signaling between the perirhinal cortex (PRC) of the MTL and visual association area TE is involved in the encoding and retrieval of item-item association memories of visual objects (Naya, Yoshida and Miyashita, 2001 and 2003). On the other hand, episodic memory was tested using a temporal-order memory task in which subjects were required to encode two visual items and their temporal order. The data of single-unit and local-field-potential recording indicated that the hippocampus (HPC) provided incremental timing signals from one item presentation to the next while the PRC signaled the conjunction of items and their relative temporal order. These results suggest converging information flows that the continuous timing signal in the HPC is conveyed to the PRC where it is integrated with item information from area TE and converted into a discrete item-based temporal order signal (Naya and Suzuki, 2011).