I would drop all (or at least the majority of) of your infect creatures unless you plan on using infect as your primary wincon (which I would not advise, given the direction of the build).

You should read my article, Building an EDH Deck. It talks a lot about the philosophy of selecting cards for an effective deck and focuses particularly on creatures. It might help you out. There's also my List of EDH Staples and Power Cards.

What is your budget for the deck? How much experience do you have with EDH?

I've got a good experience in building and playing Commander but as it comes to this deck I just come to my end of thoughts.The main problem is:What kind of stradegy including the -1/-1 counters is the most effective I should focus on to win.I can build commanders quite good but at this one I'm just confused what to do.

I think you may be focusing far too much on the -1/-1 counters. They seem to permeate every aspect of the design to the point where it is kind of interfering with the deck's ability to do anything else. I'd focus less on the counters and just make sure that the counter-related cards that you leave in the list are the best of what's available.

You might also consider Thousand-Year Elixir and Thornbite Staff to pair up with your general.

Ok.I put in The elixir and the Staff since they interact with my commander quite well.But why should I not focus on infect too since my opponent has only 10 life for my infect creatures?And on what else should I focus instead of the -1/-1 counters?

I would say if you're going to play infect, you kind of have to go all in. Cards like Corrosive Mentor serve little purpose if most of your creatures already have infect. Green/Black has some good tutors/token making/and recursion, and you could still use cards like Flourishing Defenses but to say "why couldn't I focus on infect too?" is kind of an oxymoron. You have some excellent pieces, but they need direction and end game

As jminute14 said, infect is not something you want to go half in on. You don't really want to mix between infect and regular combat damage because it makes it hard to commit to either and harder still to win outright with either.

Not every aspect of your deck has to be involved with wither or -1/-1 counters; dedicating that much board space to these themes would be less than ideal because creatures with wither tend to be less powerful/cost effective than normal creatures and just don't offer the utility of creatures like Seedborn Muse and Primeval Titan . You risk making your deck too one-dimensional and not flexible enough to deal with noncreature approaches in an efficient manner.