Hi, Can you write small source code about loading a mesh file by using CD3DMesh object ? and in last can you write code about disabling light and enabling ambient light ? Please reply.

Why not check out the Mesh sample/tutorial in the documentation and project in the /Direct3D/Tutorials folder?

// Disable Lighting
g_pD3DDevice->SetRenderState( D3DRS_LIGHTING, false );

// Ambient Lighting (sets to white)
g_pD3DDevice->SetRenderState( D3DRS_AMBIENT, D3DCOLOR_XRGB(255,255,255) );