Abstract. In this article, we present a knowledge-based system using the concept of knowledge representation and data abstraction to support Ada ~ software development. This article uses logic-based specification with objectoriented features to facilitate Ada software development. The Ada source code will be obtained through knowledgebased transformation. This system includes a frame-and-rule-oriented requirements language (FRORL), a predominance/particular methodology, and a knowledge base. FRORL uses frame representations for object-oriented modeling, applies production rules for specifying actions and constraints of real world domains, and provides a set of abstract mechanisms for the practical description of abstract relations. The predominance/particular methodology is used to support Ada software developers in performing object-oriented modeling of application domains. The knowledge base provides rules for specification checking, prototype validation, and transformation of specifications into Ada code. A real problem is given to illustrate the system.