A Vpr function regulating composition useful in the treatment of subjects infected with HIV or having AIDS, wherein the composition comprises an aminostilbazole derivative represented by the following formula [1] or a salt thereof as an active ingredient: A-B-D-E[1] wherein A represents heteroaryl or an oxide thereof, B represents ethenylene, D represents phenylene, and E represents the formula: --N(R)--SO.sub.2-G wherein G represents phenyl, R represents hydrogen, alkyl, or --COR.sup.0 (R.sup.0 represents alkyl, alkoxy, aryloxy, 5- to 6-membered heteroaryl, heteroarylmethyl, aminoalkylene, or cyclic amino alkylene)or the like.