We examined the reactions of a phosphanylalumane (>Al-P<) with chalcogen sources as a part of our investigation of the reactivity of the Al-P bonds. In the case of sulfur source, two S atoms were inserted into the Al-P bond to afford an [Al-S-P-S] heterocycle. Structural analysis and theoretical calculations revealed a charge-separated structure between the [Al](+) and [S2P](-) moieties of the [Al-S-P-S] 4-membered ring, which is different from the [B-S-P-S] ring having concrete B-S sigma-bonds in the 4-membered ring.