Ok, I know to get more speed, pay more. But I pay my ISP for 1Mbps speed but according to speedtest.net my download speed is less than 0.40Mbps and upload speed is less than 0.15Mbps. Is it suppose to be like that? Is it the total speed is the addition of both? Is there anyway I can increase the download speed by configuration?

Btw, I'm using ADSL connection.

Usuall 1Mbps is divided by eight.

You mean 8 packets or something else?

Speed depends on your internal cabling, splitter, router/modem, distance to the LEX ...
You can see in the conf from the router at which speed the connection is made
=> Data rate(Kbps)

Are you connected within busy location? ISP's market their speed by quoting ONLY THE UPPER LIMIT of the speed without telling you that it is about 40-60% lower than what you are made to believe to pay for. There are many more factors that can pull the speed down: poor hardware connnection, modem capability, overall ISP-side service load and the source FTP site load if you are downloading something, or even the browser used can affect that.

I think you should look for a better ISP.

Hope this helps.

How can I check the conf? Btw, currently I'm using Wireless connection. And there's only two computers in the network. If considering the aged cable used in the telephone line, less than 40% of the speed that I paid for is intolerable. Contacting the ISP is not so much an option since the help line seems to be busy, and late reply for emails.

ISPs always advertise the max speed you could get; over a clean line and (in the case of ADSL2+) the distance from the exchange is very important up to the 1 - 2 km. It falls off exponentially.
Note also the 'divide by 8'; that's because Mbps = Mega bits(!) per sec, not MBps = Mega Bytes per sec.
For simplicity I just divide by 10, which is simpler and closer to what you'll really get, as per my 1st sentence.
You can try getting the ISP to do (or they'll ask local telco) a line test in case it's really mucked up. They may be able to do something about it, esp if you were a business customer.
Realistically, you may just have to cough up more money if you want faster...
YMMV

Let me guess, you are using AT&T or a subsidiary of AT&T. I have AT&T 3Mbps ADSL and Charter Communications 10Mbps Cable. Since I maintain 2 separate networks for certain reasons I will not divulge, I mainly use the Charter Communications 10Mbps Cable. However the AT&T 3Mbps ADSL is actually pulling less that 1Mbps down and about .5Mbps up according to speedtest.net. I am located just south of Downtown Atlanta, so I am not far out and the LEC is about 2 miles from me. They are running copper to the curb, and then standard telephony cabling to the door. My AT&T ADSL is a full duplex 100Mbps network, where as my Charter 10Mbps cable is a Full Duplex 1000Mbps network.

I can't do something at all to increase the speed by 10%? Like increasing the bandwidth or something.