Based on the monthly data of various solar parameters e.g. sunspot numbers (SSN),Solar flux (10.7 cm), sunspot area (SA), grouped solar flares (GSF) and solar flare index (SFI) for the solar cycle 21 to the present cycle 24 (up to year 2015), a detailed correlative study has been performed. It has been found that, on monthly average basis, the SSN are highly correlated with other solar parameters (except SFI) and hence, SSN can be safely used as a solar parameter for any correlative study, until and unless there are some specific reasons to use other easily available solar parameters (or indices). As for as correlation coefficient is concerned, SSN and SFI shows distinctly different behaviour during cycles 23 and 24. Moreover, it has been found that with the progression of solar cycle, from cycle 22 to 24 the slope of the regression line between SSN and GSF or SFI decreases continuously. However, no such unidirectional change is observed in the correlation coefficient
