A dental rotary drive cutting tool, which can limitbreaking location to the shank side, and increase life spanuntil breakage, is provided. A peeso reamer (10) as thedental rotary drive cutting tool according to the presentinvention includes a cutting portion (11) formed on the tipside, a shank (12) formed in a base, and a neck part (13)formed between the cutting portion (11) and the shank (12),wherein the neck part (13) includes a tapered portion(13a), which is wider on the tip side and narrower on thebase side, and a straight portion (13b), which has aconstant thickness with the same diameter as that of theend of the tapered portion on the base side. While itbreaks at the narrowest portion of the tapered portion,this portion is a straight portion, and thus increase inlife span is possible.
