Compton scattering of high power laser and electron beams is a good test of electrodynamics in the high field region. Compton scattering occurs in the nonlinear regime if ultra high power laser pulse is scattered. Namely, an electron absorbs multiple laser photons before emitting a single photon with higher energy. In addition to the spectral shift, the theories predict the nonlinear process modifies angular distribution of scattered photons. The author's group measured angular distribution of x-ray photons produced in head-on collision of CO₂ laser and 60-Me V electron beams at Brookhaven National Laboratory, Accelerator Test Facility and confirmed that it agrees with theoretical predictions.