Did you offer them a significant amount of equity?

Don't forget that having someone working for you has to be beneficial for both of you, you talked about what you need, but you didn't talk about what you offer. Would you accept, as a worker, what you would offer as a boss?

What is your country?

@さりげない告白: No I won't like to offer equity but I can pay them good enough.

@Bebs: Thanks for guides. I live in Iran. What I offered them was equal to what other famous companies maybe offering them. But it seems I must pay them more, but I don't know how much? I don't like to over pay and do an expensive project when it wasn't needed.

Is there any sort of start up culture in Iran?

How long ago have you start hiring? For example, finding a good expert might take as long as half a year in my location (not Iran, though).

@Benjamin: Yes, there are thousands of startups and science & tech parks, etc.

@IgorG: I started about 3-4 months ago.

@Kaz: Okay I accepted that I must offer more money, but I don't know how much? 10%? 20%? 50%?

@Kaz: The problem is I don't want to give equity to my employees. In fact Im not looking for a co-founder. But I will be glad to hear about other ideas to offer them?

@Kaz, you need more perks than just salary.

@3487308 Ask yourself, if you were an awesome, expert-level developer. In a world full of companies desperate to hire them, why would they pick you? What are you offering that’s better than the other offers they can get?

Receiving equity is one of the primary reasons for joining a startup. If you're serious about creating a company, I suggest reading "The Founder's Dilemmas", by Prof. Wasserman. One of the most common sources of failure at a startup, is trying to do it by yourself. Your main role is to build a team. You can still keep 40% to 20% of the shares, depending on how successful you are, but the best are not interested in just working for you. They can do that at a stable, established company, which can pay them more.

The usual method is to give them equity in one form or another, and pay them a lot to make up for the risk that the company may go under before it gets a product to market.

@user3486308 equity isn’t just for founders. The amount might be less but early employees of startups also share equity, often in the form of an option pool.

In US common baseline for considering a job change is +20% to overall compensation (which if you'd pay cash only would be at least 2x current base salary). Don't forget to add multiplier for "I'm going to work for @#$@ boss that wants all profits for themselves". And indeed signup bonus need to account for "this job may not be around in a year"... So my guess is say average salary is 100K/year (not including bonuses/…) you'd need to offer something like 50K signup bonus + 200K/year cash to start.

You really should reconsider your position on equity. Startup culture (at least in Australia and the USA) has a reputation of long hours, rush to launch, tight deadlines etc. By giving your initial dev team equity they now have a vested interest in you and your product. A dev on salary alone will not be as enthused to work the extra hours as one who has additional interest the the company/product.

The aren't leaving just because of salary, I would bet it's mostly because they don't believe in your idea or trust you to build a successful company. The risk is then very high for them. High risk means you have to pay much more or offer other perks (like future equity, also equity doesn't mean 50%, it can be 1 or 5%). Ask yourself: would your work for your company? If it fails, you can also resort to hiring contractors or an agency to do the work. Contractors don't care if you pay them good money on time.

I think you have 2 problems that you haven't identified: 1. You don't know enough about profit-sharing arrangements to effectively offer them and that low-level of business acumen is a huge red flag to anyone seriously considering working with you. 2. You don't want to share any power. You've mentioned that you don't want to share power with equity holders. One of the key reasons to join a startup is to exert influence and have a big impact (yes, employees can have power without holding equity). You don't seem to want to offer that.

Have you considered using contractors?

I suspect you are overappreciating the value of "a good idea". Good ideas are worth next to nothing, it is the capability of turning a good idea into a good product that is. Thus, if you need people to help with that capability, then sharing equity would probably be necessary.

@user3486308, please, before moving forward with your idea try to read "Lean Startup" by Eric Ries, and "User Story Mapping" from Jeff Patton. It may help you A LOT on defining and removing risks that you may encounter with your idea.

OP is making a massive mistake if the has to drop this line here: "when they find this is a new company and there is no other member teams, they give up and leave" THEY SHOULD NOT BE THERE FOR A MEETING IF THIS IS A DEAL KILLER FOR THEM!!!!!!!!!!!!!!!!!! Startups are NOT a regular employment so MAKE PEOPLE AWARE OF IT!

Nobody wants to work for a startup for industry standard pay. There is simply too much risk involved with joining an unproven company only to get paid market value. Why would they work for that when there's no guarantee your company will make it past a year? Why would they risk being unemployed in a few months by trusting someone with no history successfully running a business? The only reason someone would do that is that they hope it will pay off later when the equity develops value. If you aren't offering that opportunity then the only thing you are offering them is risk. Bad deal.