This study investigated preschoolers' living kinds conceptualization by employing an extensive stimulus set and alternate indices of understanding. Thirty-four 3- to 5-year-olds and 36 adult undergraduates completed 3 testing phases involving 4 object classes: plants, animals, mobile, and immobile artifacts. The phases involved inquiries participants generated, what biological properties they attributed and their assignment of "alive" to the 4 classes. The study also focused on preschoolers' conceptual coherence by examining their responding across indices. Results revealed both competence and confusion in preschoolers' living kinds conceptualization relative to adults'. In addition, demonstrations of coherence across testing situations suggest that the beginnings of an abstract, biologically organized framework for understanding of living and nonliving kinds are in place in the preschool period.