AIM: To investigate the effects of 0.01% atropine eye drops on macular blood flow density and retinal thickness in children with different degrees of myopia. METHODS: This was a prospective case-control study. Sixty-four patients (112 eyes) diagnosed with myopia for the first time with 0.01% atropine eye drops before and 6 months after medication were investigated with the uncorrected distance visual acuity (UCVA), axial length (AL), spherical equivalent (SE), macular ganglion cell-inner plexiform layer thicknes (mGCIPL) using slit lamp examination and optical coherence tomography (OCT), vascular density in the macular area and the area of the avascular in the fovea using optical coherence tomography angiography (OCTA) . Changes in various indicators before and after medication were compared. RESULTS: Compared with before medication, the AL of the three groups of myopia patients increased significantly (P<0.01), the difference in low to moderate myopia group was significantly smaller than that in high myopia group.Compared with before medication, SE increased in all three groups of myopia patients, yet there was no statistically significant difference in the low-grade myopia group (P>0.05). The difference was statistically significant between the moderate myopia group and the high myopia group (P<0.01). Compared with before medication, there was no change in intraocular?pressure (IOP) among the three groups of myopic patients (P>0.05). After 6 months of medication, the central circle macular vessel density (cCVD) increased in the low myopia group and moderate myopia group (P<0.01), there was no statistically significant difference in the high myopia group (P>0.05). Before and after medication, there was no significant difference in outer circle macular vessel density (oCVD), inner circle macular vessel density (iCVD), and whole circle macular vessel density (wCVD) among the three myopia groups (P>0.05). The increase in mGCIPL was statistically significant in the low myopia group (P<0.01), but there was no statistically significant difference in the moderate myopia and high myopia groups (P>0.05).There was no significant difference in foveal avascular zone (FAZ) among the three myopia groups before and after medication (P>0.05). There was no correlation between CVD, AL, and SE in the three myopia groups (P>0.01).There was a low correlation between CVD and mGCIPL in the low myopia group (r=0.442, P<0.05), there was no correlation between CVD and mGCIPL in the moderate myopia and high myopia groups (P>0.01). CONCLUSION: 0.01% atropine can significantly reduce the rate of axial and refractive growth in children with low to moderate myopia, increase the density of central macular vessels, and increase the thickness of mGCIPL in children with low to moderate myopia.