Abstract: Two MCC heavy rain processes in 29th-30th May 2008(“0529”) and 16th-17th June 2010(“0616”) in Guizhou Province have been analyzed on the base of the TBB of FY2-D meteorological satellite,conventionally observational data and the NCEP 1°×1° reanalysis data.The results showed that the development processes of two MCC heavy rainfalls were different.In the“0529” MCC case,several meso-β-scale convective cells grew up and combined to generate MCC.In the“0616” MCC case,the single convective cell grew up quickly,finally converted to the MCC.The two cases had different effects on the synoptic system at low level.Cold air took hold in “0529” MCC case,while southwester low-level jet took hold in “0616” MCC case.After diagnostic analysising,we also found that the convergence of dynamic conditions and moisture was acute,so convection current and short-term heavy rainfall were strong in “0529” MCC case.While the convergence of dynamic conditions and moisture extended high at vertical,water-vapor persistently transferred long,which formatted the stormy weather for long time.The frontogenesis function of the two MCC case has been analyzed.It showed that in “0529” MCC case,elongation deformation Af had obvious effect on frontogenesis.In “0616” MCC case,elongation deformation Af and shear deformation Bf were both crucial to the formation of frontogenesis.