You create particle systems when you want to model an object or effect that can best be described as a large collection of similar objects behaving in a similar fashion. Obvious examples of such effects include rain and snow, but other equally valid examples include water, smoke, ants, and even crowds of people.
On the Create panel, click Spray, Snow, Super Spray, Blizzard, PArray, or PCloud to create a particle system. Spray and Snow exist primarily for compatibility with earlier releases of 3ds Max, and are superseded by Super Spray and Blizzard.
To create a particle system, first choose Create menu 
Particles Spray or Snow.
These are the basic steps for creating a particle system:
- Create a particle emitter. All particle systems require an emitter. Some particle systems use the particle system icon as the emitter while others use an object you select from the scene as the emitter.
- Determine the number of particles. You set parameters such as birth rate and life span to control how many particles can exist at any given time.
- Set particle shape and size. You can select from many standard particle types (including metaballs) or you can select an object to be emitted as a particle.
- Set initial particle motion. You can set the speed, direction, rotation, and randomness of particles as they leave the emitter. Particles can also be affected by animation of the emitter.
- Modify particle motion. You can further modify the motion of particles after they leave the emitter by binding the particle system to a space warp in the Forces group, such as Path Follow, or make them bounce off a deflector in the Deflectors space warp group, such as UDeflector. Attention: When you use forces and deflectors together, always bind the forces before the deflectors.Tip: If the particles don't follow the emitter after it's moved, then change any Path Follow parameter. The motion will be applied to the particles.
Rain and Snow
Create rain and snow using Super Spray and Blizzard. These particle systems are optimized for droplet (Super Spray) and tumbling flake (Blizzard) effects. Add space warps such as Wind to create spring rains or winter storms.
Bubbles
Create bubbles by using the Bubble Motion options of Super Spray. If you require good rendering speed, consider using constant or tetra particles. If you require bubble detail, consider using opacity-mapped facing particles, instanced spheres, or metaparticles.
Flowing Water
You generate flowing liquid effects by setting Super Spray to generate closely packed metaparticles. The metaparticles blob together forming a stream. Add a Path Follow space warp to send the stream down a trough.
Explosions
Particle Array (PArray) uses another object as its particle emitter. You can set the particle type to use fragments of the emitter object to simulate the object exploding.
Volume Effects
Particle Cloud (PCloud) constrains its particles within a specified volume. You can use Particle Cloud to generate bubbles in a glass of soda, or bees buzzing inside a jar.
Crowds
Super Spray, Blizzard, Particle Array, and Particle Cloud can use instanced geometry as their particle type. You can create a stream of ants, a flock of birds, or a cloud of dandelion seeds using instanced geometry particles.