Tejal,
The value 0 (zero) towards left of the axisY is the label of axisY whereras the value 0 (zero) below the axisX is the label of axisX. As both the values x & y of dataPoint are 0 (zero), the dataSeries line is being drawn from (0,0) co-ordinate. If you like the axisX scale to be started from 0, you can set minimum of axisX to 0.
—-
Manoj Mohan
Team CanvasJS