Embedding capacity is one of the important factors that affect the information hiding perfomance.An improved information hiding scheme for VQ-compressed index map images based-on joint neighboring coding(JNC)technique is proposed to increase the embedding capacity.The proposed method embeds secret data by using the difference values ranging between the current VQ-compressed index and its four neighboring indices.Experimental results show that the proposed method increases the embedding capacity significantly compared with Chang’s and Yang’s method.The proposed method obtains 2.11 to 3.16 times embedding capacity compared to Chang’s method with only a 5.13%to 13.10%increas of the bit rate.As a result，the value of embedding-efficiency is increased on average from 0.10 in Chang’s method to 0.26 in the proposed method.