  Studies of charm and beauty production in ep collisions with a center-of-mass
energy of 318 GeV are reported from the two HERA collaborations, H1 and ZEUS.
The analyses make use of both the HERA-I data sample recorded between 1996 and
2000 and a sample from HERA-II, which started in 2003. The cross sections
measured by both H1 and ZEUS experiments are compared with next-to-leading
order QCD calculations. The measurement of the charm and beauty contributions
to the proton structure function is also presented. The comparison to
next-to-next-to-leading order (NNLO) calculations shows agreement within the
errors.
