Abstract.
We present the preliminary results of our multi-wavelength analyses
of the young stellar population associated with the star forming
complex Sh2-252. The NIR and MIR data sets from 2MASS and 
Spitzer-IRAC, MIPS identified 131 Class I, 400 Class II sources and
a slitless spectroscopic survey detected 61  Hα emission
line stars. The spatial distribution of these YSOs shows that
majority of them are concentrated within the sub-regions Sh2-252 A,
C and E. The optical CMD and SED analyses show that these YSOs show
an age spread of ∼ 5 Myr and a mass range of 0.3 M⊙ -
2.5 M⊙.  The CMD and SED analyses as well as the Class
I/Class II fraction show that the sub-regions  have a  median age of
∼ 2-3 Myr, suggesting  same evolutionary status for them. We
report an enhanced concentration of Class I sources having  a median
age of ∼ 0.5 Myr between the ionization fronts of Sh2-252 and
Sh2-252A. We presume that  the combined expansion process  of these
two &hii; regions in opposite directions has triggered  the new star
formation within the collected material between them.
 
Key words:stars -- formation -- pre-main-sequence: ISM -- Hⅈregions