Suspended　particulate　matter　(SPM)　content　in　waterbody　is　one　of　the　indicators　for　measuring　the　degree　of　water　pollution.　It　plays　an　important　role　in　endogenous　release　and　water　environment　change　of　lakes.　In　this　study,　the　temporal　and　spatial　distribution　characteristics　of　SPM　in　Erhai　Lake　in　different　seasons,　different　regions　and　different　water　depths　were　studied.　The　causes　of　SPM　were　analyzed,　and　its　influence　mechanism　on　the　water　quality　of　Erhai　Lake　was　also　clarified.　The　obtained　results　indicated　that:　(1)　The　seasonal　variation　of　SPM　content　followed　the　pattern　as:　summer　>　autumn　>　winter　>　spring,　with　algae　growth　being　the　main　reason　for　the　obvious　higher　content　of　SPM　in　summer.　In　addition,　the　regional　distribution　showed　the　variation　trends　as:　central　>　northern　≥　southern,　surface　>　middle　>　bottom.　(2)　The　relationship　between　SPM　content　and　dissolved　organic　matter　in　overlying　water　indicated　that　migration　and　transformation　of　SPM　were　important　factors　affecting　the　behavior　of　dissolved　organic　matter　in　overlying　water.　(3)　The　partition　coefficient　(Kd)　of　dissolved　organic　nitrogen　(DON)　(lg　Kd=6.12±0.47)　was　higher　than　that　of　dissolved　total　nitrogen　(TDN)(lg　Kd=5.70±0.48),　indicating　that　DON　possessed　a　higher　particle　reactivity.　DON　can　be　absorbed　and　utilized　by　phytoplankton,　thereby　producing　a　higher　SPM　concentration,　and　in　turn　posing　a　risk　of　lake　eutrophication.　The　obtained　results　indicated　that　the　influence　deriving　from　inflow　river　and　wet　deposition　on　SPM　distribution　was　relatively　small.　It　was　mainly　affected　by　endogenous　metabolism.　Higher　water　temperature,　higher　pH　(8.98),　and　lower　dissolved　oxygen　concentration　were　considered　to　contribute　to　the　increment　of　algae-related　SPM　concentration.　©　2019,　Editorial　Board,　Research　of　Environmental　Sciences.　All　right　reserved.