A low threshold stretched-pulses mode-locked Erbium-doped fiber ring cavity femtosecond laser with small positive-dispersion Er3+-doped fiber was demonstrated.By introducing the small positive-dispersion fiber,the pulse energy and spectrum width were improved,the sideband of the spectrum was effectively restrained,and the self-starting pump power threshold was only 90 mW.The passive mode-locked continued to a pump power level as low as 29 mW.Self-starting mode-locked pulses with time duration of 175 fs,spectral width of 40 nm and repetition rate of 33 MHz were achieved by using this stretched-pulse configuration.