The sodium-aluminium borosilicate glass and quantum-dot (QD)-doped fiber are fabricated by the two-step high temperature annealing method. The QDs within the fiber have a size of 4.73 nm±0.25 nm and their absorption and emission peaks are at 1450 nm and 1500 nm, respectively. The absorption spectra, photoluminescence (PL) spectra and PL peak intensity versus pumping power are measured. The attenuation coefficient within the fiber at 980 nm pumping power and PL peak intensity and peak wavelength versus fiber length are also measured. The wavelength-dependent attenuation coefficient, pumping excitation threshold and saturation power in the QD-doped fiber are determined. The experimental phenomena is explained from the aspects of energy-level transition, surface effects, and so on.