In this paper, a new steganographic method that preserves the first-order statistics of the cover is proposed. Suitable for the passive warden scenario, the proposed method is not robust to any change of the stego object. Besides the relative simplicity of both encoding and decoding, high and adjustable information hiding rate can be achieved with our method. In addition, the perceptual distortion caused by data embedding can be easily minimized, such as in the mean squared error criterion. When applied to digital images, the generic method becomes a sort of LSB hiding, namely the LSB + algorithm. To prevent the sample pair analysis attack, the LSB + algorithm is implemented on the selected subsets of pixels to preserve some important high-order statistics as well. The experimental results of the implementation are promising.