The Law Society of Scotland said proposals put forward by the Scottish Government would lead to a situation where weapons are untraceable and the exact total held not known.
Brought forward by justice secretary Kenny MacAskill earlier this year, the Air Weapons and Licensing (Scotland) Bill seeks to control access to air weapons.
Broadly following the principles of existing firearms legislation, the new rules will mean only those considered fit to obtain a licence will be allowed to own an air weapon.
The Scottish Government said the proposals had been the subject of extensive talks with Police Scotland, the Scottish Police Authority and the Gun Trade Association.
But the Law Society said the legislation would not achieve the desired effect of reducing air weapon crime.
The society are concerned that anyone possessing an air weapon would be required to apply for a certificate covering all weapons held – however, there would be no requirement for each individual weapon to be listed on that certificate.
Archie MacIver, convener of the society’s licensing law committee said: “Under the proposals, the air weapon certificate will apply to the person, not the weapon.
“In practical terms, without a narration or description of each individual weapon, the police will have no way of knowing how many air weapons are in circulation and, in the absence of serial numbers, as with shotguns, these weapons will remain untraceable.”
Moves to tighten up the laws surrounding air weapons follow the death of two-year-old Andrew Morton, who was hit in the head by an airgun pellet in Glasgow in 2005.
The toddler was being carried by his older brother as they watched fire engines near their home in Easterhouse.
The man found guilty of the offence was drug addict Mark Bonini who was later jailed for life for murder, and ordered to serve at least 13 years in prison.
Meanwhile, the Law Society said separate proposals in the bill for alcohol licensing would not address practical difficulties encountered in the pub trade.
Mr MacIver added: “There are issues under the current alcohol licensing regime and the 2005 act which have not been addressed by this bill, particularly where a business is to be transferred.
“At the moment, where a tenant who is the premises licence- holder just ups and leaves, there is no provision to transfer that licence.
“In those circumstances, we would like to see any person who wishes to become a holder of a premises licence being able to apply for that licence to be transferred to them.”
A Scottish Government spokeswoman said: “We believe that the Air Weapons and Licensing Bill provides a reasonable, clear and consistent approach to licensing.
“The Scottish Government has long held the belief that air weapons should be licensed and is committed to doing so. We are interested to see responses to the bill, which will be considered in detail.”