In this thesis a compiler called SPASCAL is implemented which translates source programs in a simple Pascal-like language called SPASCAL into target programs in the VAX assembly language. This thesis clearly describes the main aspects of a compiler: lexical analysis and syntactic analysis, including the symbol-table routines and the error-handling routines. This thesis uses regular expressions to define the lexical structure and a context-free grammar to define the syntactic structure of SPASCAL. The compiler is constructed using syntax-directed translation, context-free grammars and a set of semantic rules. SPASCAL Compiler is written with standard C in UNIX. / Department of Computer Science