  For the first time, we statistically study the properties of ephemeral
regions (ERs) and quantitatively determine their parameters at the emergence
stage based on a sample of 2988 ERs observed by the \emph{Solar Dynamics
Observatory}. During the emergence process, there are three kinds of kinematic
performances, i.e., separation of dipolar patches, shift of ER's magnetic
centroid, and rotation of ER's axis. The average emergence duration, flux
emergence rate, separation velocity, shift velocity, and angular speed are 49.3
min, 2.6 $\times$ 10$^{15}$ Mx s$^{-1}$, 1.1 km s$^{-1}$, 0.9 km s$^{-1}$, and
0$\degr$.6 min$^{-1}$, respectively. At the end of emergence, the mean magnetic
flux, separation distance, shift distance, and rotation angle are 9.3 $\times$
10$^{18}$ Mx, 4.7 Mm, 1.1 Mm, and 12$\degr$.9, respectively. We also find that
the higher the ER magnetic flux is, (1) the longer the emergence lasts, (2) the
higher the flux emergence rate is, (3) the further the two polarities separate,
(4) the lower the separation velocity is, (5) the larger the shift distance is,
(6) the slower the ER shifts, and (7) the lower the rotation speed is. However,
the rotation angle seems not to depend on the magnetic flux. Not only at the
start time, but also at the end time, the ERs are randomly oriented in both the
northern and the southern hemispheres. Besides, neither the anticlockwise
rotated ERs, nor the clockwise rotated ones dominate the northern or the
southern hemisphere.
