Among all routing protocols in wireless multimedia sensor networks（ WMSNs）

multipath routing protocols（ MRP） are suitable for increasing reliability of data transmission and achieve load balancing

which provide QoS guarantee for multimedia data flow.Classification methods of MRP is introduced

routing protocols are divided into three kinds

which are active routing protocol

responding routing protocol

and encoding routing protocol

by considering routing establishment occasion and data transmission technique

detailed explanation and analyzation of the above MRP are carried out respectively.Finally

characteristics of these protocols are compared

and the further research issues of MRP are pointed out.