Thank you Amleto for your suggestion.

I just go through the url that you had given and I tried by giving the path in INCLUDEPATH variable but didn't succeed.

Then I use QLibrary class to include my library and it's symbol. It compiles successfully but didn't call my library function this I came to know by checking it in Application output window of Qt, it shows :

"LDR: LdrpWalkImportDescriptor() failed to probe F:\SlaveDeviceSimulator\File_transfer_DLL.dll for its manifest, ntstatus 0xc0150002"

Here "F" is my drive and "File_transfer_DLL.dll" is my dll file.

Can anybody help me where i am going wrong.
If code is needed I will post it.

Thanks for enlightening me!
Vinod.