With　the　development　of　wireless　communication　technology,　indoor　tracking　technology　has　been　rapidly　developed.　Wits　presents　a　new　indoor　positioning　and　tracking　algorithm　with　channel　state　information　of　Wi-Fi　signals.　Wits　tracks　using　motion　speed.　Firstly,　it　eliminates　static　path　interference　and　calibrates　the　phase　information.　Then,　the　maximum　likelihood　of　the　phase　is　used　to　estimate　the　radial　Doppler　velocity　of　the　target.　Experiments　were　conducted,　and　two　sets　of　receiving　antennas　were　used　to　determine　the　velocity　of　a　human.　Finally,　speed　and　time　intervals　were　used　to　track　the　target.　Experimental　results　show　that　Wits　can　achieve　the　mean　error　of　0.235　m　in　two　different　environments　with　a　known　starting　point.　If　the　starting　point　is　unknown,　the　mean　error　is　0.410　m.　Wits　has　good　accuracy　and　efficiency　for　practical　applications.　©　2021　by　the　authors.　Licensee　MDPI,　Basel,　Switzerland.