Is Creativity or Strategic Thinking the most important quality to have as an advertising professional? and Why?

there are many aspects for the quality assurance, to be creative you have to got the problem solving skills and concept mapping methodologies to enhance the percentage of audiences perception. for sure strategic thinking is required for marketing aspect.

Neither are particularly important.

You have a choice of advertising agencies to hire:  one is rightly renowned for it's creativity, the other for its unmatched knowledge of what works and what doesn't.  Which one are you going to hire?  Answer, it's almost always the second one.  Creativity can only compete with knowledge when you are doing unusual things, like launching a totally new industry.  The success of a TV ad is not generally dependent on how original it is.  (Yes there are exceptions, but that's what they are - exceptions.) 

"Strategy" is a word bandied around the marketing industry a great deal, but much of the time it isn't really appropriate.  True strategic thinking in marketing means things like subtly linking the marketing campaigns of two different brands and your main corporate social responsibility programme in a way that makes it very difficult for your main competitor to respond.  It doesn't mean deciding whether to use direct mail or pay per click, or producing a campaign plan which is in-budget and consistent with the brand portfolio.

Having said all that, strategic thinking obviously wins.  Creativity is useless if it's aimed in the wrong direction.  (Plus, being a good strategic thinker necessarily requires a certain amount of creativity.)

I Believe strategy and creativity is like two sides of the coin, but still i would love to give more number to strategy as this paves the path to reach the goal or objectives. Once strategy is finalized we have to be creative enough to implement the strategic decision.

An advertising strategy is a campaign developed to communicate ideas about products and services to potential consumers in the hopes of convincing them to buy those products and services. This strategy, when built in a rational and intelligent manner, will reflect other business considerations (overall budget, brand recognition efforts) and objectives (public image enhancement, market share growth) as well. 

Strategic thinking will drive your creativity to achieve your objectives. 

You can produce an efficient campaign with strategic thinking alone, but not with creativity alone. Creativity will add to the strategic thinking by touching your audience differently, and increasing your awareness. 

yes. because it the hart of work

You only need creativity, if your creative enough to can create almost anything, like a good strategy plan on how to sell your product if your a brand manager, you can create good artwork if your an artist, you can create good civil structure if your an engineer and so on. Remember creativity is a general term to define someone's ability to create things or tools for their trade it not always related to artwork and designs.