  In the paper, we apply the $k_T$ factorization approach to deal with the
$B\to K$ transition form factor with tensor current in the large recoil
regions. Main uncertainties for the estimation are discussed and we obtain
$F_T^{B\to K}(0)=0.25\pm0.01\pm0.02$, where the first error is caused by the
uncertainties from the pionic wave functions and the second is from that of the
B-meson wave functions. This result is consistent with the light-cone sum rule
results obtained in the literature.
