Hi all ! COM port on my A3000 seems not to be OK. So is there a software for PC to transfer data using an LPT connection ? What else can I do ? - Will a common ISA ethernet card work in ISA16 slot of A3000 ?
If your ultimate goal is to simply move files between your PC and Amiga. There are many avenues available.
Repair your serial port. It's probably a simple chip replacement and the A3000's chips are socketed.
You can search Aminet for words like "transfer", "PC network", "parallel network", Serial network", parnet, sernet, etc. You get the idea. You may have to solder up a suitable cable, these are usually detailed with the software package. Amiga Forever has a transfer package, I think, for the parallel port.
Ethernet has already been covered.
I use 100MB Zip drives. You will need a USB version for the PC, and, a SCSI version for the Amiga. The PC will be plug-n-play. Almost any of us can help you with a mountlist file for the Amiga, or, consider downloading Jaztools on the Amiga. These drives are commonly (and cheaply) available in thrift stores and on eBay. In fact, they are so plentiful, you might buy several of each kind to ensure you get a pair that works.

If the files are small, do it with 720k floppies. You will need a USB floppy for the PC. You can use CrossDos on the Amiga or MultiDos (my favorite and free on Aminet).
Find one of Mechwares Amiga card readers on eBay. (Mech, there is still demand for these! Good job.)
If you are just wanting files from online, consider ways to go directly online with your Amiga. Browsing is slow and behind the times, but, Aminet works great.
The Amiga is about choice, flexibility, and user options.