Based on spectrum holography structure proposed by Mazurenko, an improved femtosecond spectrum holography structure is proposed. The recording and readout of the spectrum holography by femtosecond pulses with both the spatial and temporal information is deduced, it shows if a filter is put on the spectrum plane of the modified structure, spatial information included in the femtosecond pulse can be converted in to temporal information and output. The results can be applied in many fields, such as ultrashort pulse shaping, ultrafast optical communication and optical information processing etc.