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In this talk, our knowledge of the initial conditions under which massive
star formation takes place is reviewed. Massive stars are born in
massive clumps of giant molecular clouds (GMCs), hence first the properties
of GMCs are summarized. As an early stage of molecular clouds,
infrared dark clouds (IRDCs) have been discovered a decade ago as dark
patches in MIR images of the galactic plane and many studies of the
physical conditions within them have been conducted recently. Without
the guidance of MIR absorption, large scale, unbiased cold dust surveys
can be used as well to identify massive cold clumps. In the absence of
indicators of ongoing massive star formation, like compact HII regions
and bright IR sources, these clumps are the most promising objects for
the study of the initial conditions of massive star formation. Current
observational approaches to find IR quiet clumps and their physical and
chemical properties are reviewed.
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