This study was aim to investigate the fertilization biology of Istanbul Medlar variety. For this purpose, firstly pollen production capacity and morphological homogeneity were assessed (hemocytometer slide). The pollen viability was tested with TTC and IKI staining methods. Pollen germination experiments were carried out in different medium with different sucrose concentration (agar in plate method) during 2 h, 6 h, 12 h and 24 h period. The number of anthers in a flower 36.5, pollen number in an anther 160.55 and pollen number in a flower 12753.8 were found. Morphological homogeneity was high with 98%. Pollen viability rates varied between 94% (TTC) and 96% (IKI). Contents of medium V: 20% sucrose 1% agar-agar+5 ppm boric acid and 24 hours incubation duration were stated as optimum pollen germination rate and tube growth.