The tau neutrino is one of the least studied particle in the Standard Model.
Current tau neutrino-nucleon cross section measurement suffer large $\sim 30\%$ statistical and $\sim 50\%$ systematic uncertainties.
In near future statistical uncertainty will be reduced to a few \% by the SHiP experiment, or by the experiments such as SHiP.
DsTau (NA65) experiment at CERN aims to reduce the systematic uncertainty on tau neutrino-nucleon cross section through investigating a precise measurement on tau neutrino production, $Ds\rightarrow\tau+\nu_{\tau}$ differential production cross section with tungsten target.
The uncertainty of the tau neutrino flux will be reduced to 10 \% from 50\%.
Collaboration will collect $2.3\times10^{8}$ proton interactions with tungsten target and study about $10^5$ charm associated interactions.
A pilot run was performed in 2018 Aug and collecting about a tenth of final statistics to perform full analysis chain.
Here the analysis stream and the analysis status of 2018 Aug pilot run will be described.