No one can answer my question!
i have already fixed this problem. And now i want to share my experience about it to everyone

Very easy, we lost 5 minutes for it
Step 1: You ensure that your netbook has updated and upgrade
Step 2: Fix the conflicting between modemmanager and gobi-loader:
open terminal and type in: sudo gedit /lib/udev/rules.d/77-mm-usb-device-blacklist.rules
insert 2 following line below into:
# Samsung Gobi 2000 QDL device (VL176)
ATTRS{idVendor}=="05c6", ATTRS{idProduct}=="9244", ENV{ID_MM_DEVICE_IGNORE}="1"
Note: idvendor and idproduct is difference among companys, and you can take it by using command "lsusb"
Step 3: Install gobi-loader: sudo apt-get install gobi-loader
Step 4: Copy firmware to /lib/firmware/gobi (certainly, you must creat the gobi folder before copying). Firmware files (3 files), you can download here
http://www.mediafire.com/?6a71jnj8695cz7jAfter download, you extract and copy these file: qualcomm/images/samsung/0/UQCN.mbn; qualcomm/images/samsung/UMTS/*.* into folder gobi.
Step 4: shutdown computer
Step 5: Restart and Enjoy!

Above is my solution, you can reference if you want