AN EMB-145 GROUND CREW REPEATEDLY ASKED THE CAPTAIN TO RELEASE BRAKES PREPARING FOR PUSHBACK FROM THE GATE AND THEN LEAVE WITH NO CHOCKS INSTALLED. GROUND CREWS ARE NOT FOLLOWING SOP.

Narrative

WHEN READY TO PUSHBACK FROM GATE; THE GND CREW GAVE ME THE SIGNAL TO RELEASE THE PARKING BRAKE IN ORDER TO ATTACH THE ACFT TO THE TUG. I RELEASED THE BRAKE AND THEN TURNED MY ATTN TO OTHER THINGS IN THE COCKPIT. WHEN I LOOKED BACK OUTSIDE; THE TUG HAD NOT YET BEEN CONNECTED AND THE RAMP CREW HAD LEFT THE ACFT. I RESET THE PARKING BRAKE. WHEN THEY RETURNED; THEY AGAIN GAVE ME THE SIGNAL TO RELEASE THE BRAKE AND I COMPLIED. ONCE AGAIN THE CREW LEFT THE ACFT WITH NO CHOCKS INSTALLED; AND THE BRAKE RELEASED. I RESET THE BRAKE. FOR THE THIRD TIME; THE CREW RETURNED; I RELEASED THE BRAKE; AND THE CREW LEFT. THIS TIME THEY ENTERED THE BAGGAGE COMPARTMENT WITHOUT LETTING ME KNOW TO SET THE BRAKE. THE GND CREWS HAVE BEEN LEAVING THE ACFT WITH THE PARKING BRAKE RELEASED AND CHOCKS REMOVED FOR THE PAST FEW WKS NOW. I HAVE CONTACTED OPS AND RAMP SUPERVISION NUMEROUS TIMES TO REMIND THE GND PERSONNEL TO HAVE US SET THE BRAKE BEFORE THEY LEAVE; BUT NOTHING HAS CHANGED. PLEASE CONTACT THE PEOPLE IN CHARGE AT ZZZ TO ENSURE THEIR CREWS ARE TRAINED PROPERLY AND ARE THINKING ABOUT THEIR OWN SAFETY AS WELL AS EVERYONE ELSE'S SAFETY.