  The weak cosmic censorship conjecture in the near-extremal BTZ black hole has
been tested by the test particles and fields. It was claimed that this black
hole could be overspun. In this paper, we review the thermodynamics and weak
cosmic censorship conjecture in BTZ black holes by the scattering of the scalar
field. The first law of thermodynamics in the non-extremal BTZ black hole is
recovered. For the extremal and near-extremal black holes, due to the
divergence of the variation of the entropy, we test the weak cosmic censorship
conjecture by evaluating the minimum values of the function $f$. Both of the
extremal and near-extremal black holes cannot be overspun.
