Abstract: Scheduling of aperiodic tasks is an important research topic in real time systems The study of scheduling algorithms for aperiodic tasks in real time systems is summarized These algorithms are classified into two categories: server based algorithms and slack based algorithms Each algorithm and its variations are discussed, and especially their characteristics and performance are analyzed By comparing and analyzing these different algorithms, researchers and designers of real time systems can gain useful information Finally, some suggestions for future research in scheduling aperiodic tasks are made