Abstract: Aiming at the essential problems of the design of adaptive spatial steganography, this paper proposes an adaptive spatial steganographic algorithm without synchronizing the side information, combining with Cannys edge detection algorithm and the Syndrome Trellis Code (STC). Firstly, the parameters of Cannys algorithm are obtained on the basis of the factors, including the length of the secret message, the cover image, and so on; then Cannys algorithm is used to select the edge region of the cover image. Moreover, the embedding distortions of the edge and non-edge pixels are defined respectively. Finally, the STC is used to embed the secret message in multiple Least Significant Bit (LSB) planes of the pixels. The experimental results illustrate that, under the condition of four kinds of embedding rates, when resisting common universal steganalysis, the proposed method performs better than other three existing methods, and is comparable to the Spatial-UNIversal WAvelet Relative Distortion (S-UNIWARD) under the condition of small embedding rates.