I just received my Jadeite Pendant and it's beautiful, but the box says Made in China. Is That were my pendant was made?

Aloha.  A great, and fair, question.  And the answer in your case is, No.  Your Jadeite originated in Myanmar, Burma and was likely carved there.
But before further discussing Jade, let me further my explanation about your box labeling.  In dealing day-to-day with Estate, Vintage, and Antique pieces of jewelry we would like to provide each piece in its original box.  Unfortunately, that is usually not possible.  Either the original box has been long since discarded, or it is in such bad condition as to be unusable.  We source packaging through a provider who acquires fine and attractive presentation boxes for pendants, rings, bracelets, watches, and so on from suppliers worldwide, including China.  When we receive an order of packages we usually will remove the "Made in China" label to prevent confusion between the origin of the box versus the origin of the item.  In your case, the pendant display case was "Made in China" - is of excellent quality, by the way, and we merely missed one of the labels.  
But more to your Jade and Jade, generally.  There are numerous sources for Nephrite and Jadeite Jade across the globe, and Jade in its "Raw" form is purchased by buyers around the world.  These buyers may again retail the raw Jade, or they may transform the raw Jade into a beautifully carved piece of jewelry or other item.  China, incidentally, produces some of the world's most beautiful pieces of jade jewelry, and many of our Jade pieces can be traced to Chinese carvers.  Nonetheless, we thought it important to distinguish between the source of packaging versus the source of the item contained in the packaging.  ​