The inner product encry ption scheme can achieve fine-grained access control on ciphertext.For the problem that the existing inner product encry ption scheme has poor security and low decry ption efficiency,this paper proposes an inner product encry ption scheme with adaptively secure based on the dual sy stem encry ption method.The scheme is based on bilinear mapping on prime order groups.In the secret key generation algorithm of the scheme,we propose a sharing technique of random vectors and generate a secret key for each component of the attribute vector; and an encry ption algorithm with a constant size ciphertext is designed.Under the k-Lin assumption,the method of the experimental sequence is used to prove that the scheme is adap-tively secure.The decry ption algorithm of the scheme requires only six bilinear pairs.Compared with the existing schemes,the decry ption efficiency has been greatly improved.