In this paper we address the following question regarding the regularity of geodesics in the space of Kähler potentials. Given a geodesic which is highly regular, and has smooth boundary value, can we expect that it is actually smooth? We construct an example to show that the answer to the question is "no".As discovered by Semmes[20] and Donaldson[9], (1.1) can be written as a homogenous complex Monge-Ampère equation. DenoteThen we can consider a curve ϕ ∈ C 1 ([0, 1]; H) as a function defined on S × V , by letting Φ(τ, * ) = ϕ(Re τ ).