The annual average values of I^st  harmonic amplitudes of high amplitude wave trains for kiel and Halaekala neutron monitor station have been used to see their variation with the annual average magnitude of the sunspot number for the interval 1989-2003. This analysis very clearly supports the earlier finding that the diurnal amplitude are significantly smaller during the low sunspot activity period. We found  the clear cut evidence of significant positive co-relation the sunspots number and Ist harmonic amplitude. The diurnal phase of daily variation of cosmic rays for the high latitude station kiel as well as for the low latitude station haleakala for the entire period of study has also found co-related with much higher positive positive co-relation.