What will happen when power factor is leading in distribution of power?

If their is high power factor, i.e if the power factor is close to one:
a)Losses in form of heat will be reduced,
b)Cable becomes less bulky and easy to carry, and very cheap to afford, &
c)It also reduces over heating of tranformers.

I think if in a distribution line if pf becomes leading then voltage leval increase so it can cause some damages to the receiving side.

When the power factor is leading, the capacitive kVAr is more than the Inductive kVAr and this still has to be supplied by the source. As kVA is the vector sum of kW and kVAr, still for the given kW, you have to produce more kVA. Alternately, for the given kVA, you can only convert partially into useful work.

Secondary effects are voltage boost in the system, availability of stored energy to feed the fault in case of a fault, increase in the asymmetrical component of fault current, increasing thus the peak value of the fault current, etc.