In this paper we examine polarity licensing of the interrogatives in Budai Rukai (Kucapungan variety). It is shown that in certain morphosyntactic environments interrogatives are licensed as polarity items and are interpreted as indefinites. We specifically investigate two types of polarity licensing, the first with overt triggers and the second without overt triggers. By providing typological analyses along the line of Tsai (1997a, 1997b), our examination of syntactic and morphological properties concludes that Rukai exhibits characteristics of polarity licensing at the syntactic, morphological and phrasal levels.