What i've to do that a label plots near by the data point??

1. Assuming your (x,y,z) worksheet is already normalized, i.e. x+y+z=1 in data1, make a new worksheet (X2,Y2,L). L is for your labels.
2. Set the column values of X2 and Y2 such that:
X2=data1_a[i]+data1_b[i]*0.5
Y2=data1_b[i]*sqrt(3)*0.5
(Here, data1_a for x, data1_b for y.)
3. Create a scattergram of (X2,Y2,L), change the symbol size to 0, and set the X and Y axis ranges as 0 to 1.
4. Merge your ternary graph and the scattergram. Move the scattergram layer where you wish, and make the axes and tick labels invisible.