First laws of thermodynamics in IR Modified H\v{o}rava-Lifshitz gravity

We study the first law of thermodynamics in IR modified H\v{o}rava-Lifshitz spacetime. Based on the Bekenstein-Hawking entropy, we obtain the integral formula and the differential formula of the first law of thermodynamics for the Kehagias-Sfetsos black hole by treating $\omega$ as a new state parameter and redefining a mass that is just equal to $M_{ADM}$ obtained by Myung\cite{YSM2} if we take $\alpha =3\pi \mathrm{/}8$.