Abstract: The present paper is an attempt to sum up materials about CIMS, which have been published in the period of 1966--1982. The text consists of six sections, namely:1. Instrumental aspect of CIMS, which involves recent development in respectof ion source, sample introduction and combined techniques with GC, LC andcollision induced dissociation.2. Fundamentals of CIMS, which includes basic theory of proton transfer reac-tion, influence of molecular structure upon its proton afinity and fragmentationof quasi-molecular ions.3. Reagents, which are classified into four groups: protonation reagents, char-ge transfer reagents, polycomponent reagent systems and special reagents. Herea brief account on their behavior in CI source and availability for analysis hasbeen given.4. Classification of ion--molecular reactions observed under CI conditions.5. Mass spectra of common compound classes. Here the spectrum characteristicand mechanism on formation of main ions have been described in detail.6. Recent development analytical application of CIMS, which involves structural determination of thermolabile compounds, trace analysis, identification offunctional group by neutral loss and selective reaction with reagent, determina-tion of double bond site and distinction of stereoisomers.