The Programming language for symmetric cryptographic algorithms (PLSCA) is proposed. The de- tailed speci¯cation of the syntax of PLSCA is presented, and the cipher of IDEA is described using PLSCA as an example. Using PLSCA, the cryptography designers could describe the structure of symmetric cryptographic algo- rithms in a formal way, exchange their ideas and algorithm details, test and analyze the symmetric cryptographic al- gorithms conveniently and rapidly. PLSCA may improve the testing e±ciency of new algorithms. It is adapt to as- sist the design and automatic analysis for symmetric cryp- tographic algorithms, and it may be used as a standard language to submit new algorithms to the evaluation sta®.