In several applications such as multimedia transmission and deep space communications, some data may need more protection than the rest because of the different importance of the data. Such applications raise the need for fountain codes with unequal error protection (UEP).The operation mechanism of the unequal error protected fountain codes based on block duplication is analyzed, and an improved selection strategy of information symbols is proposed to improve the protection of more important bits (MIB) in local area. Degree 1 encoded symbols are selected from MIB and a certain number of degree 2 encoded symbols are chosen from MIB and less important bits(LIB), respectively. Simulation results show that compared with the existing method， the proposed scheme perform better on decoding MIB without reducing the decoding of LIB while reserving a better unequal recovery time (URT) property.