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We present spectral line mapping observations toward four massivestar-forming regions (Cepheus A, DR21S, S76E and G34.26+0.15), with the IRAM 30meter telescope at 2 mm and 3 mm bands. Totally 396 spectral lines from 51molecules, one helium recombination line, ten hydrogen recombination lines, and16 unidentified lines were detected in these four sources. An emission line ofnitrosyl cyanide (ONCN, 14$_{0,14}$-13$_{0,13}$) was detected in G34.26+0.15,as first detection in massive star-forming regions. We found that the$c$-C$_{3}$H$_{2}$ and NH$_{2}$D show enhancement in shocked regions assuggested by evidences of SiO and/or SO emission. Column density and rotationaltemperature of CH$_{3}$CN were estimated with the rotational diagram method forall four sources. Isotope abundance ratios of $^{12}$C/$^{13}$C were derivedusing HC$_{3}$N and its $^{13}$C isotopologue, which were around 40 in all fourmassive star-forming regions and slightly lower than the local interstellarvalue ($\sim$65). $^{14}$N/$^{15}$N and $^{16}$O/$^{18}$O abundance ratios inthese sources were also derived using double isotopic method, which wereslightly lower than that in local interstellar medium. Except for Cep A,$^{33}$S/$^{34}$S ratio in the other three targets were derived, which weresimilar to that in the local interstellar medium. The column density ratios ofN(DCN)/N(HCN) and N(DCO$^{+}$)/N(HCO$^{+}$) in these sources were more than twoorders of magnitude higher than the elemental [D]/[H] ratio, which is1.5$\times$10$ ^{-5}$. Our results show the later stage sources, G34.26+0.15 inparticular, present more molecular species than earlier stage ones. Evidence ofshock activity is seen in all stages studied.

Millimeter Spectral Line Mapping Observations Toward Four Massive Star Forming HII Regions