To improve the anomaly intrusion detection system using system calls, this study focuses on Neuro-Fuzzy learning using the soundex algorithm which is designed to change feature selection and variable length data into a fixed length learning pattern. That is, by changing variable length sequential system call data into a fixed length behavior pattern using the soundex algorithm, this study conducted back-propagation neural networks with fuzzy membership function. The Neuro-Fuzzy and N-gram techniques are applied for anomaly intrusion detection of system calls using sendmail data of UNM to demonstrate its performance.