at starting rotor is stationary, due to its inertia it will 
require more torque to rotated and torque is proportional 
to armature current
so requires more starting current

Dear Mr. Gajanan, as you are dealing with more machineries, 
i want to stress some points:
During starting of motor:

the armature(rotor) is stationary, and it does not having 
any magnetic property to resist the applied rotational 
frequency at that time.

so it will act as a conductor fixed at rotating magnetic 
field and produce some eddy current loss, and with in short 
period of time, it will develope some anti rotional effect 
to resist the rotational field, ie: rotating with same 
direction to reduce the eddy curent.Thats why after 
starting current reduces.

inertia of the rotor also having some major role on the 
starting current. The gap between rotor and stator having 
role on the starting current and initial power factor.

as in the initial conditions the motor is at rest,the speed 
of the motor is zero.
           
        using KVL equation,
                           V=Eb+IaRa,Eb=back EMF
                                     Ia=armature current
                                     Ra=armature resistance
(very small),V=input supply(around 220V dc)
      Initially speed=0
    implies Eb=0
      Ia=(V/Ra)   which is very high value,since V is high 
and Ra is very small.
            Hence starting resistance or 3 point starter 
are used.

V=Eb+IaRa,Eb=back emf

At starting there is no back Emf
And V (Normal Supply Voltage)=220V(single Phase)
Ia = Armature Current
Ra = Armature resistance(Usually less (.2 to .5 ohms)

From the Above equation,
Ia = (V-Eb)/Ra
Since Eb is Zero, the above eqn will become
Ia = V/Ra  (220/0.5 = 440A)
So at starting the current thru the armature is very high 
to minimise this we are using the starters.

What the persons above said is true mathematically.
If you look at it as in theory, we know a DC Machine can act
as a Motor as well as a Generator. So as the Current is 
supplied to the conductors present in a magnetic field, a
Force starts to act on the current carrying conductor. This
current forces the Rotor to rotate. At this time the only
Voltage is the supplied Voltage. As soon as the motion
starts there has to be an Emf induced which directly depends
on the speed of rotor. This induced voltage is called
Counter EMF or the Back EMF, which is absent at the instance
the motor is supplied a current. This EMF in effect acts
opposite to the Supplied Voltage. So whatever Drop of
volatge is in The resistance of Rotor wires is due to the
Total Supplied Voltage and Resistance is pretty low so the
current at the start is very high

when we turn on a motor,it induces a relatively high 
current to get over the inertia of the motor. this induced 
current is estimated to be 7*rated current if the motor was 
in  direct to line connection