The　first　high-performance　seismometer　on　Mars,　deployed　by　InSight,　has　been　working　for　nearly　two　Martian　years.　However,　the　recorded　seismic　data　are　substantially　affected　by　the　natural　frequencies　of　the　lander.　To　analyze　the　effect　of　the　natural　frequencies　of　the　lander　on　specific　components　of　the　seismic　data,　we　have　built　a　simplified　finite-element　model　of　the　lander　to　conduct　modal　analyses.　Three　natural　frequencies　are　modeled　by　comparing　them　with　those　identified　from　the　observed　data.　These　natural　frequencies　are　nonconstant　and　temperature　dependent,　which　can　be　explained　as　an　elastic　modulus　reduction　of　the　solar　panels　(35%　at　most)　and/or　the　property　changes　of　the　ground　media　beneath　the　lander　due　to　a　daily　air　temperature　variation　of　approximately　100　K　on　Mars.　Compared　with　the　previous　studies　based　on　the　empirical　models　before　the　launch,　our　results　can　quantitatively　evaluate　natural　modes　and　their　temperature　dependency.　Thus,　these　analyses　are　helpful　in　avoiding　the　potential　interference　of　natural　frequencies　and　improving　the　reliability　of　seismic　data　applications.　　©　2023　Society　of　Exploration　Geophysicists.