diff --git a/onnxruntime/core/providers/vitisai/imp/ep_context_utils.cc b/onnxruntime/core/providers/vitisai/imp/ep_context_utils.cc
index 19921fd522914..ab31aa313cf6d 100644
--- a/onnxruntime/core/providers/vitisai/imp/ep_context_utils.cc
+++ b/onnxruntime/core/providers/vitisai/imp/ep_context_utils.cc
@@ -1,6 +1,5 @@
 // Standard headers/libs.
 #include <fstream>
-#include <filesystem>
 #include <sstream>
 #include <cctype>
 #include <cstring>
@@ -190,7 +189,8 @@ std::string SerializeOrigialGraph(const GraphViewer& graph_viewer) {
     }
   }
   j_obj["orig_graph_name"] = graph_viewer.Name();
-  j_obj["orig_model_path"] = PathToUTF8String(graph_viewer.ModelPath().ToPathString());
+  // TODO: platform dependency (Linux vs Windows).
+  j_obj["orig_model_path"] = graph_viewer.ModelPath().string();
 
   // XXX: `ModelProto::SerializeToString` will lose some info,
   // e.g., ModelProto.opset_import.
@@ -263,7 +263,7 @@ ONNX_NAMESPACE::ModelProto* CreateEPContexModel(
   p_attr_3->set_name(kONNXModelFileNameAttr);
   // p_attr_3->set_type(onnx::AttributeProto_AttributeType_STRING);
   p_attr_3->set_type(ONNX_NAMESPACE::AttributeProto::STRING);
-  p_attr_3->set_s(fs::path(graph_viewer.ModelPath().ToPathString()).filename().string());
+  p_attr_3->set_s(graph_viewer.ModelPath().filename().string());
   // Attr "notes".
   auto p_attr_4 = ONNX_NAMESPACE::AttributeProto::Create();
   p_attr_4->set_name(kNotesAttr);
@@ -435,7 +435,7 @@ void CreateEPContexNodes(
     auto p_attr_3 = ONNX_NAMESPACE::AttributeProto::Create();
     p_attr_3->set_name(kONNXModelFileNameAttr);
     p_attr_3->set_type(ONNX_NAMESPACE::AttributeProto::STRING);
-    p_attr_3->set_s(fs::path(graph_viewer.ModelPath().ToPathString()).filename().string());
+    p_attr_3->set_s(graph_viewer.ModelPath().filename().string());
     p_node_attrs->emplace(kONNXModelFileNameAttr, *p_attr_3);
     // Attr "partition_name".
     auto p_attr_6 = ONNX_NAMESPACE::AttributeProto::Create();
@@ -595,7 +595,7 @@ bool FusedGraphHasEPContextNode(
   return false;
 }
 
-const Path& GetTopLevelModelPath(const GraphViewer& graph_viewer) {
+const fs::path& GetTopLevelModelPath(const GraphViewer& graph_viewer) {
   const auto& graph = graph_viewer.GetGraph();
   const Graph* p_graph = &graph;
   while (p_graph->IsSubgraph()) {
diff --git a/onnxruntime/core/providers/vitisai/include/ep_context_utils.h b/onnxruntime/core/providers/vitisai/include/ep_context_utils.h
index f453038d45f06..61a595cf1ae15 100644
--- a/onnxruntime/core/providers/vitisai/include/ep_context_utils.h
+++ b/onnxruntime/core/providers/vitisai/include/ep_context_utils.h
@@ -1,6 +1,7 @@
 #pragma once
 
 // Standard headers/libs.
+#include <filesystem>
 #include <vector>
 #include <string>
 #include <memory>
@@ -67,7 +68,7 @@ bool GraphHasEPContextNode(const Graph&);
 bool FusedGraphHasEPContextNode(
     const std::vector<IExecutionProvider::FusedNodeAndGraph>&);
 
-const Path& GetTopLevelModelPath(const GraphViewer&);
+const fs::path& GetTopLevelModelPath(const GraphViewer&);
 
 bool GetEPContextModelFileLocation(
     const std::string&, const PathString&, bool, PathString&);
diff --git a/onnxruntime/core/providers/vitisai/vitisai_execution_provider.cc b/onnxruntime/core/providers/vitisai/vitisai_execution_provider.cc
index fbc24c34ec33e..0d048824a9f56 100644
--- a/onnxruntime/core/providers/vitisai/vitisai_execution_provider.cc
+++ b/onnxruntime/core/providers/vitisai/vitisai_execution_provider.cc
@@ -82,7 +82,8 @@ void VitisAIExecutionProvider::LoadEPContexModelFromFile() const {
 void VitisAIExecutionProvider::PrepareEPContextEnablement(
     const onnxruntime::GraphViewer& graph_viewer) const {
   if (model_path_str_.empty()) {
-    model_path_str_ = GetTopLevelModelPath(graph_viewer).ToPathString();
+    // TODO: platform dependency (Linux vs Windows).
+    model_path_str_ = ToPathString(GetTopLevelModelPath(graph_viewer).string());
   }
   std::string backend_cache_dir, backend_cache_key;
   get_backend_compilation_cache(model_path_str_, graph_viewer, info_, kXCCode, backend_cache_dir, backend_cache_key, backend_cache_data_);
@@ -123,7 +124,8 @@ void VitisAIExecutionProvider::FulfillEPContextEnablement(
 std::vector<std::unique_ptr<ComputeCapability>> VitisAIExecutionProvider::GetCapability(
     const onnxruntime::GraphViewer& graph_viewer, const IKernelLookup& /*kernel_lookup*/) const {
   bool is_ep_ctx_model = GraphHasEPContextNode(graph_viewer.GetGraph());
-  model_path_str_ = GetTopLevelModelPath(graph_viewer).ToPathString();
+  // TODO: platform dependency (Linux vs Windows).
+  model_path_str_ = ToPathString(GetTopLevelModelPath(graph_viewer).string());
   if (GetEPContextModelFileLocation(
           ep_ctx_model_path_cfg_, model_path_str_, is_ep_ctx_model, ep_ctx_model_file_loc_)) {
     if (is_ep_ctx_model) {