In order to improve the robust of image information hiding method and to increase the hiding capacity,a High Significant Bit Hiding(HSBH) algorithm against SPA(Sample Pair Analysis) analysis is proposed.The idea and the principle of SPA are introduced,and the HSBH algorithm is analyzed,results show that the HSBH drawback can not resist the SPA attack.So an improved HSBH algorithm is presented.The experimental results indicate that,considering the SPA idea,the correct rate of detection is nearly 95% when the embedding rate is more than 3%.And no matter how much message is embedded by the improved algorithm,SPA steganalysis will get a very small estimation value and form an incorrect judgment to hide information,so that the information can be hidden securely.