Steganography is a technique for embedding secret messages into carriers. Linguistic steganography is a branch of text steganography. Research on attacking methods against linguistic steganography plays an important role in information security (IS) area. In this paper, a linguistic steganography detecting algorithm using statistical language model (SLM) is presented. An experiment to detect text segments generated by linguistic steganography systems NICETEXT, TEXTO and Markov-chain-based is carried out. The result of our experiment shows when the text segment size is 2K and 5K, the detecting accuracies are found to be 93.9% and 96.3% respectively.