Cryptography has the crucial importance in modern info-society. The merits of chaos have brought a new means for the design of cryptography. As a brilliant achievement of modern cryptography, chaotic cryptography has great potential and becomes more and more popular in info-security field. The corresponding problems about cryptography and chaos theory are discussed in detail. The theory and method of the chaos-based cryptography is analyzed, the recent research development of chaos-based cryptography is expatiated. Both advantages and disadvantages of chaos-based cryptography are summarized and the future research trends are outlined.