Authors: Xiaolei Li (Auburn Univerisity), Chen Shi (Auburn University)

Magnetic switchbacks, characterized by reversals of magnetic field direction, are widely observed in the inner heliosphere by Parker Solar Probe (PSP). With PSP reaching perihelia near 10Rs, observations from the first 24 encounters enable studies of near-Sun switchback evolution at r>10Rs. We construct a switchback catalog within 10<r<55Rs by identifying magnetic field reversals with stable field magnitude and strahl-electron polarity. Statistical analysis shows that switchback Alfvénicity decreases with increasing radial distance, consistent with increasing Alfvénic imbalance of the solar wind beyond the Alfvén critical point. Meanwhile, switchback occurrence rate and spatial size increase with distance, suggesting continued generation and expansion during solar wind propagation. At a given radial distance, the fraction of solar wind streams that contain switchbacks is positively correlated with background solar wind radial velocity (V_R) and Alfvén Mach number (M_A), while the local occurrence rate is mainly controlled by M_A. These results suggest that switchback patches preferentially form in faster and higher- M_A solar wind. The spatial size of switchbacks shows no clear dependence on M_A or V_R, implying that their size evolution is not solely determined by source conditions but controlled by the solar wind expansion. Solar activity influences switchback evolution through changes in background solar wind properties, with a larger fraction of higher- M_A switchbacks during solar minimum. We further identify anisotropy with respect to the background magnetic field direction: the local occurrence rate and spatial size are approximately twice as large in the perpendicular direction as in the parallel direction, indicating anisotropic magnetic topology of switchback patches.