CN Tower is the highest artificial construction in the world, and there are frequent direct lightning strikes. Toronto University, McMaster University and LRG paid their attention on this fact, and started the collaboration. LRG supplied a hand made optical measurement system to measure the velocity of discharges to CN Tower, and replaced it with ALPS in 1996. LRG could get three data sets in summer of1996, and the results of the analysis will be shown in the near future.