  We investigate the tracker configuration optimization for the Circular
Electron Position Collider (CEPC), a proposed Higgs and $Z$ factory. Fixing the
construction cost comparable to that of the baseline detector design and
considering the benchmark channels ($Z\rightarrow f\bar{f}$, $WW$ fusion with
$H\rightarrow f\bar{f}$, $ZH\rightarrow\nu\bar{\nu}f\bar{f}$, and
$t\bar{t}\rightarrow b\bar{b}\mu\nu_\mu ud$) of various operating modes of the
CEPC, we obtain the optimal tracker radius that provides the best average
resolution of the track momentum or jet energy. The optimal tracker radii for
track momentum resolution range from 1.59\,m to 1.73\,m and for jet energy
resolution from 1.82\,m to 1.97\,m, depending on the benchmark channels.
Compared to the jets, the tracks prefer a smaller radius and a longer length
because the track momentum resolution degrades more significantly than jet
energy resolution in the forward region. The benchmark channel for $Z$-pole
prefers a smaller radius and longer length compared to other benchmark channels
because the final state particles at the $Z$-pole have a more forward
distribution. We also analyze the scaling behavior of the optimal tracker
configuration at floating construction cost and observe a weak dependence.
