I want to know the main reason that makes a project failed and what makes a project to succeed too. I am waiting for your guidance please.

Some Key Reasons Project Fail include:
Unidentified risks
Unidentified stakeholders
Poorly designed project schedule (Using Microsoft Project and not linking the tasks correctly, for example)
Scope creep

The problem is most of the projects are considered failure because the incorrect project objectives definition. For example "growth in market share 5% in the current year". Most of the objectives are related to the product, not to the project. The only objetives you must define for a project is related to scope, time, cost and quality. Obviously you must derive them from the business or strategic objectives like I stated before.

People - Every thing created for people by people , It is important to have right people in right place to success

Right Product Manager/Analyst - Create right business/project objective
Right Project Manager - Plan and Execute project with in agreed/acceptable constraints
Right Team with right skills execute/perform the task
Right Stakeholders - Support/co-operate for project success

Depending on the definition of success (scope, cost and time as well as achieving business outcomes and delivering benefits). In Australia we always give the Opera House Project as an example; while the project exceeded its budget, and was late, it yet delivered its intended outcomes and benefits.

If you look at a project in a similar fashion to cooking/preparing a meal, you need the right ingredients at the right time with the right amount. It is quite a delicate science and art. Hence, to ensure success the team needs a solid understanding of what needs to be achieved and how it will be achieved. Stakeholders expectations need to be set and managed throughout the project. Customer (end product user) need to be engaged and having a sense of ownership. The team needs to work collaboratively and be open and honest about any risks and issues. And the most important factor is the right level of sponsorship.